What is kenning?
A kenning (Modern Icelandic pronunciation: [cʰɛnːiŋk]; derived from Old Norse) is a type of circumlocution, in the form of a compound that employs figurative language in place of a more concrete single-word noun. Kennings are strongly associated with Old Norse and later Icelandic and Anglo-Saxon poetry.
They usually consist of two words, and are often hyphenated. For example, Old Norse poets might replace sverð, the regular word for “sword”, with a more abstract compound such as “wound-hoe” (Egill Skallagrímsson: Höfuðlausn 8), or a genitive phrase such as randa íss “ice of shields” (Einarr Skúlason: ‘Øxarflokkr’ 9). The term kenning has been applied by modern scholars to similar figures of speech in other languages too, especially Old English.

Difference and similarities of epic and lyric
Epic poetry tries to tell a grand narrative and is closely related to oral storytelling. The Odyssey and The Iliad are two famous examples of epic poetry from ancient Greece. Though some poets still work with epic poetry, it's not as popular as lyric poetry, which is one of the most common types of poetry today. Lyric poetry is interested in communicating a brief moment packed with significance through the use of intense, imagistic language.

Epic poetry is poetry that has lots factual based information while the lyric poetry is when the poetry is very factual and has lots of rymes. Also, each sentence in the lyric poetry has ten lines while the other type of poetry has only 3. Get it, theres a BIG difference!!!
Differences of Beowulf and Grendal
Besides both being ferocious fighters, Grendal and Beowulf are very different. Grendal is described as a descendant of Cain, the first murderer in the Bible. This would make him evil in the eyes of an audience of his day. He lives in the wilds, away from human society and his attack on Herot is motivated by his hatred for joyous celebration. On the other hand, Beowulf is a man who has deep affection for his other humans. He is not merely an incredibly strong fighter but he is equally skilled with words. He defends Unferth, talks like an ambassador when returning home, and,towards the end of his life, gives an accounting of his actions that sounds like an elder statesman. He is loyal, compassionate and the only character who talks about God. Grendal seems capable only of destruction. Beowulf becomes a wise and successful king who is loved by his countrymen.
Similarities
Although Beowulf is a hero and Grendel is an antihero, they are actually parallels and have a few similarities. First, they are both outcasts and choose to operate alone. Second, they both are filled with anger as they go into battle: Grendel is offended by the happy men's merrymaking's and Beowulf is offended by the monster and his vicious killing. Third, they are both proud and boastful, though in Beowulf's case he has reason to be whereas Grendel does not.