The Transistor is a staple in modern computing. A transistor is a semiconductor device used to amplify and switch electronic signals and electric power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. The transistor has become a fundamental building block of modern electronic devices, and is omnipresent in modern electronic systems. The need for the transistor arose due to its’ predecessor, the vacuum tube’s numerous inefficiencies. Vacuum tubes were notoriously unreliable, due to the heat they generated, and in larger instillations, one failed every couple hours or so. In order to counteract the problem, two Bell Laboratory engineers went to work. In 1947, John Bardeen and Walter Brattain created the transistor. It was smaller, more reliable, and consumed much less power; it made the vacuum tube obsolete. A few short months later, Bell associate William Shockley created the junction transistor, and together the three men were awarded the 1956 Nobel Prize in Physics.
Moore's Law observes that over the history of computing technology, roughly every two years the number of transistors in dense integrated circuitry doubles. In 1971 Intel created the 4004, the first microprocessor. A microprocessor is a piece of integrated circuitry that contains all the functions of a computer's CPU. the Intel 4004 housed 2,300 transistors, in a chip that was only 2 inches large. Just a few decades prior it would've taken an entire room worth of equipment to do what the two inch 4004 could do. Intel was comissined to create a chip not only capable of running on computers but a variety of products as well. For example, the Intel 4004 was used in traffic light controllers, blood analyzers, and even in the NASA Pioneer 10 deep space probe; this inventioned nearly singlehandedly paved the way for the PC, smartphone, and other miniature computers. By April of the following year (1972) Intel had upgraded to the Intel 8008 which had increased the number of transistors present to a whopping 3,500. Next is the Intel 8080, then the Intel 80186, so on and so forth; the rapid rate of growth supported Moore's findings.
By 2001 the number of times we were able to double the speed these microprocessors were able to produce reached 18,500. In 2010, Intel created the Quad-Core Itanium Tukwila microprocessor, which was the first of it's kind to house two billion transistors. This unprecedented rate of growth has not been experienced in an other technilogical field in our history. Intel's 62-Core Xeon Phi is arguably the most capable chip on the market, housing 5 billion transistors, a mind-boggling figure. If we were to stay in line with Moore's Law, by the end of the decade microprocessors will house 100 billion transistors. By 2027, one trillion. The human race will continue to advance at an astonishing rate.

Citations:
Upgrading and Repairing PCs, 17th Edition by Mueller, Scott March 24, 2006

Intel.com

http://www.eugenecomputergeeks.com
"Intel Proceccor Chip Comparison" by Roberts, Alisha April 20, 2012