1- Briefly explain Electronic Cash

A system that allows a person to pay for goods or services by transmitting a number from one computer to another. Like the serial numbers on real dollar bills, the digital cash numbers are unique. Each one is issued by a bank and represents a specified sum of real money. One of the key features of digital cash is that, like real cash, it is anonymous and reusable. That is, when a digital cash amount is sent from a buyer to a vendor, there is no way to obtain information about the buyer. This is one of the key differences between digital cash and credit card systems. Another key difference is that a digital cash certificate can be reused.

2- Briefly explain ActiveX Control

ActiveX control is a control using Microsoft ActiveX technologies. An ActiveX control can be automatically downloaded and executed by a Web browser. ActiveX is not a programming language, but rather a set of rules for how applications should share information. Programmers can develop ActiveX controls in a variety of languages, including C, C++, Visual Basic, and Java. An ActiveX control is similar to a Java applet. Unlike Java applets, however, ActiveX controls have full access to the Windows operating system. This gives them much more power than Java applets, but with this power comes a certain risk that the applet may damage software or data on your machine. To control this risk, Microsoft developed a registration system so that browsers can identify and authenticate an ActiveX control before downloading it. Another difference between Java applets and ActiveX controls is that Java applets can be written to run on all platforms, whereas ActiveX controls are currently limited to Windows environments.

3- Briefly explain Firewalls
A firewall is a software or hardware device that protects your computer from internet dangers, such as (among many, many others) viruses, spyware, and hackers. Think of it like a thick stone castle wall - no one can get through it except at heavily guarded gates. Any data going from the internet to your computer must first pass through the firewall, where it is carefully scanned for threats. If the firewall detects any dangers, it blocks the data. Firewalls close off all of the unused ports, channeling all internet traffic through only a handful of open ports. Furthermore, the firewall filters all data moving through these ports, meaning that it examines all the data packets for the proper security authorization. Any data that fails to meet these security requirements is not allowed through the firewall onto your computer. Firewalls also make sure that any personal or sensitive information leaving your computer is protected. It does this by encrypting the information. The information can be decrypted when it arrives at its legitimate destination. Any hackers or spyware that intercept the information on the way, however, gets only scrambled data that it can't read or use.
4- Briefly explain Cookies A cookie is a small file that is stored on a client's computer. That means that whenever a user visits your web site, you can secretly stash a file with information on their hard drive. This file can contain almost any information you want - including user info, site statistics, or even your own name, for those with vanity problems. We can see how this could potentially be an easy target for hackers because of the possibilities it opens up. One security trick to prevent abuse is that cookies can only be accessed by the domain that created them. This means that, for example, ASP101.com can only access (read from and write to) cookies that ASP101.com created. Generally, this is not a problem at all, but what if you work on two different sites on different domains that share user info, that is stored in cookies? You could, of course, just duplicate user info, but what if you want the user to only have to register on one site, and be automatically registered on the other? Or if they share the same user database, and you want to auto-login users? Sharing cookies across domains is ideal for this situation.

5- Briefly explain Enterprise Application Integration and database
Enterprise Application Integration) Hooking up applications within an enterprise. EAI software acts as a hub that translates data and messages between different applications. The need for EAI arose as companies sought to exchange information between separate 'silos' of automation, such as ERP and CRM systems. EAI is regarded as more tightly coupled and inflexible than emerging alternatives based on web services. Enterprise Application Integration Refers to various techniques that are used to make information systems work together in the large enterprise. For example, when companies acquire other companies, disparate systems have to be integrated. Within a company, newly developed systems must work with legacy systems, and separate systems developed independently in the past must often be tied together to provide required information and services. When information systems are integrated, business intelligence can be gleaned across the entire enterprise.

6- Briefly explain Magnetic Strip Cards
A magnetic stripe card is a type of card capable of storing data by modifying the magnetism of tiny iron-based magnetic particles on a band of magnetic material on the card. The magnetic stripe, sometimes called swipe card or magstripe, is read by physical contact and swiping past a magnetic reading head. A number of International Organization for Standardization standards, ISO/IEC 7810, ISO/IEC 7811, ISO/IEC 7812, ISO/IEC 7813, ISO 8583, and ISO/IEC 4909, define the physical properties of the card, including size, flexibility, location of the magstripe, magnetic characteristics, and data formats. They also provide the standards for financial cards, including the allocation of card number ranges to different card issuing institutions.

Briefly explain Smart Cards
A small electronic device about the size of a credit card that contains electronic memory, and possibly an embedded integrated circuit (IC). Smart cards containing an IC are sometimes called Integrated Circuit Cards (ICCs). Smart cards are used for a variety of purposes, including: Storing a patient's medical records Storing digital cash Generating network IDs (similar to a token) To use a smart card, either to pull information from it or add data to it, you need a smart card reader, a small device into which you insert the smart card.

7- Briefly explain Return on Investment (ROI)
A performance measure used to evaluate the efficiency of an investment or to compare the efficiency of a number of different investments. To calculate ROI, the benefit (return) of an investment is divided by the cost of the investment; the result is expressed as a percentage or a ratio. In finance, rate of return (ROR), also known as return on investment (ROI), rate of profit or sometimes just return, is the ratio of money gained or lost (whether realized or unrealized) on an investment relative to the amount of money invested. The amount of money gained or lost may be referred to as interest, profit/loss, gain/loss, or net income/loss. The money invested may be referred to as the asset, capital, principal, or the cost basis of the investment. ROI is usually expressed as a percentage.

8- Briefly explain pros and cons of PayPal
PayPal is without doubt the most widely-known and widely-used payment processor for Internet marketing. They offer a wide range of benefits, which makes them a very popular choice, but there are a few drawbacks to using PayPal, too. As payment systems go PayPal is pretty easy to set up compared to standard merchant accounts. This is one of the major reasons why so many people choose to use them. They don’t require you to fill out and sign a ton of paperwork, they don’t do a credit check, and the money you earn can be instantly available for withdrawal at an ATM if you have their debit card.

9- Briefly explain Asymmetric Encryption System
The problem with secret keys is exchanging them over the Internet or a large network while preventing them from falling into the wrong hands. Anyone who knows the secret key can decrypt the message. One answer is asymmetric encryption, in which there are two related keys--a key pair. A public key is made freely available to anyone who might want to send you a message. A second, private key is kept secret, so that only you know it. Any message (text, binary files, or documents) that are encrypted by using the public key can only be decrypted by applying the same algorithm, but by using the matching private key. Any message that is encrypted by using the private key can only be decrypted by using the matching public key.

This means that you do not have to worry about passing public keys over the Internet (the keys are supposed to be public). A problem with asymmetric encryption, however, is that it is slower than symmetric encryption. It requires far more processing power to both encrypt and decrypt the content of the message.
Briefly explain Symmetric Encryption System Symmetric encryption is the oldest and best-known technique. A secret key, which can be a number, a word, or just a string of random letters, is applied to the text of a message to change the content in a particular way. This might be as simple as shifting each letter by a number of places in the alphabet. As long as both sender and recipient know the secret key, they can encrypt and decrypt all messages that use this key.

10 - Briefly explain Telnet Telnet is a system for logging onto a remote computer through the Internet. There are lots of reasons to do this. Telnet allows you to access computers all over the world and use the resources you find on those computers. You could use telnet to access Brand X while on vacation to check your mail. You can use it to play games, to join chat lines, or you can use it to access and modify web pages if you have a web site. Telnet does this by simulating a UNIX terminal connected to the other computer via the Internet. So what you see in Telnet is the same thing as what you would see if you were at a terminal hooked directly to the other computer.
Briefly explain FTP
File Transfer Protocol (FTP) is a standard network protocol used to copy a file from one host to another over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server. FTP users may authenticate themselves using a clear-text sign-in protocol but can connect anonymously if the server is configured to allow it. The first FTP client applications were interactive command-line tools, implementing standard commands and syntax. Graphical user interface clients have since been developed for many of the popular desktop operating systems in use today

1- Briefly explain Electronic Cash

A system that allows a person to pay for goods or services by transmitting a number from one computer to another. Like the serial numbers on real dollar bills, the digital cash numbers are unique. Each one is issued by a bank and represents a specified sum of real money. One of the key features of digital cash is that, like real cash, it is anonymous and reusable. That is, when a digital cash amount is sent from a buyer to a vendor, there is no way to obtain information about the buyer. This is one of the key differences between digital cash and credit card systems. Another key difference is that a digital cash certificate can be reused.

2- Briefly explain ActiveX Control

ActiveX control is a control using Microsoft ActiveX technologies. An ActiveX control can be automatically downloaded and executed by a Web browser. ActiveX is not a programming language, but rather a set of rules for how applications should share information. Programmers can develop ActiveX controls in a variety of languages, including C, C++, Visual Basic, and Java. An ActiveX control is similar to a Java applet. Unlike Java applets, however, ActiveX controls have full access to the Windows operating system. This gives them much more power than Java applets, but with this power comes a certain risk that the applet may damage software or data on your machine. To control this risk, Microsoft developed a registration system so that browsers can identify and authenticate an ActiveX control before downloading it. Another difference between Java applets and ActiveX controls is that Java applets can be written to run on all platforms, whereas ActiveX controls are currently limited to Windows environments.

3- Briefly explain Firewalls
A firewall is a software or hardware device that protects your computer from internet dangers, such as (among many, many others) viruses, spyware, and hackers. Think of it like a thick stone castle wall - no one can get through it except at heavily guarded gates. Any data going from the internet to your computer must first pass through the firewall, where it is carefully scanned for threats. If the firewall detects any dangers, it blocks the data. Firewalls close off all of the unused ports, channeling all internet traffic through only a handful of open ports. Furthermore, the firewall filters all data moving through these ports, meaning that it examines all the data packets for the proper security authorization. Any data that fails to meet these security requirements is not allowed through the firewall onto your computer. Firewalls also make sure that any personal or sensitive information leaving your computer is protected. It does this by encrypting the information. The information can be decrypted when it arrives at its legitimate destination. Any hackers or spyware that intercept the information on the way, however, gets only scrambled data that it can't read or use.
4- Briefly explain Cookies A cookie is a small file that is stored on a client's computer. That means that whenever a user visits your web site, you can secretly stash a file with information on their hard drive. This file can contain almost any information you want - including user info, site statistics, or even your own name, for those with vanity problems. We can see how this could potentially be an easy target for hackers because of the possibilities it opens up. One security trick to prevent abuse is that cookies can only be accessed by the domain that created them. This means that, for example, ASP101.com can only access (read from and write to) cookies that ASP101.com created. Generally, this is not a problem at all, but what if you work on two different sites on different domains that share user info, that is stored in cookies? You could, of course, just duplicate user info, but what if you want the user to only have to register on one site, and be automatically registered on the other? Or if they share the same user database, and you want to auto-login users? Sharing cookies across domains is ideal for this situation.

5- Briefly explain Enterprise Application Integration and database
Enterprise Application Integration) Hooking up applications within an enterprise. EAI software acts as a hub that translates data and messages between different applications. The need for EAI arose as companies sought to exchange information between separate 'silos' of automation, such as ERP and CRM systems. EAI is regarded as more tightly coupled and inflexible than emerging alternatives based on web services. Enterprise Application Integration Refers to various techniques that are used to make information systems work together in the large enterprise. For example, when companies acquire other companies, disparate systems have to be integrated. Within a company, newly developed systems must work with legacy systems, and separate systems developed independently in the past must often be tied together to provide required information and services. When information systems are integrated, business intelligence can be gleaned across the entire enterprise.

6- Briefly explain Magnetic Strip Cards
A magnetic stripe card is a type of card capable of storing data by modifying the magnetism of tiny iron-based magnetic particles on a band of magnetic material on the card. The magnetic stripe, sometimes called swipe card or magstripe, is read by physical contact and swiping past a magnetic reading head. A number of International Organization for Standardization standards, ISO/IEC 7810, ISO/IEC 7811, ISO/IEC 7812, ISO/IEC 7813, ISO 8583, and ISO/IEC 4909, define the physical properties of the card, including size, flexibility, location of the magstripe, magnetic characteristics, and data formats. They also provide the standards for financial cards, including the allocation of card number ranges to different card issuing institutions.

Briefly explain Smart Cards
A small electronic device about the size of a credit card that contains electronic memory, and possibly an embedded integrated circuit (IC). Smart cards containing an IC are sometimes called Integrated Circuit Cards (ICCs). Smart cards are used for a variety of purposes, including: Storing a patient's medical records Storing digital cash Generating network IDs (similar to a token) To use a smart card, either to pull information from it or add data to it, you need a smart card reader, a small device into which you insert the smart card.

7- Briefly explain Return on Investment (ROI)
A performance measure used to evaluate the efficiency of an investment or to compare the efficiency of a number of different investments. To calculate ROI, the benefit (return) of an investment is divided by the cost of the investment; the result is expressed as a percentage or a ratio. In finance, rate of return (ROR), also known as return on investment (ROI), rate of profit or sometimes just return, is the ratio of money gained or lost (whether realized or unrealized) on an investment relative to the amount of money invested. The amount of money gained or lost may be referred to as interest, profit/loss, gain/loss, or net income/loss. The money invested may be referred to as the asset, capital, principal, or the cost basis of the investment. ROI is usually expressed as a percentage.

8- Briefly explain pros and cons of PayPal
PayPal is without doubt the most widely-known and widely-used payment processor for Internet marketing. They offer a wide range of benefits, which makes them a very popular choice, but there are a few drawbacks to using PayPal, too. As payment systems go PayPal is pretty easy to set up compared to standard merchant accounts. This is one of the major reasons why so many people choose to use them. They don’t require you to fill out and sign a ton of paperwork, they don’t do a credit check, and the money you earn can be instantly available for withdrawal at an ATM if you have their debit card.

9- Briefly explain Asymmetric Encryption System
The problem with secret keys is exchanging them over the Internet or a large network while preventing them from falling into the wrong hands. Anyone who knows the secret key can decrypt the message. One answer is asymmetric encryption, in which there are two related keys--a key pair. A public key is made freely available to anyone who might want to send you a message. A second, private key is kept secret, so that only you know it. Any message (text, binary files, or documents) that are encrypted by using the public key can only be decrypted by applying the same algorithm, but by using the matching private key. Any message that is encrypted by using the private key can only be decrypted by using the matching public key.

This means that you do not have to worry about passing public keys over the Internet (the keys are supposed to be public). A problem with asymmetric encryption, however, is that it is slower than symmetric encryption. It requires far more processing power to both encrypt and decrypt the content of the message.
Briefly explain Symmetric Encryption System Symmetric encryption is the oldest and best-known technique. A secret key, which can be a number, a word, or just a string of random letters, is applied to the text of a message to change the content in a particular way. This might be as simple as shifting each letter by a number of places in the alphabet. As long as both sender and recipient know the secret key, they can encrypt and decrypt all messages that use this key.

10 - Briefly explain Telnet Telnet is a system for logging onto a remote computer through the Internet. There are lots of reasons to do this. Telnet allows you to access computers all over the world and use the resources you find on those computers. You could use telnet to access Brand X while on vacation to check your mail. You can use it to play games, to join chat lines, or you can use it to access and modify web pages if you have a web site. Telnet does this by simulating a UNIX terminal connected to the other computer via the Internet. So what you see in Telnet is the same thing as what you would see if you were at a terminal hooked directly to the other computer.
Briefly explain FTP
File Transfer Protocol (FTP) is a standard network protocol used to copy a file from one host to another over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server. FTP users may authenticate themselves using a clear-text sign-in protocol but can connect anonymously if the server is configured to allow it. The first FTP client applications were interactive command-line tools, implementing standard commands and syntax. Graphical user interface clients have since been developed for many of the popular desktop operating systems in use today