Most states have laws that classify different levels of felonies, from the least serious to the most serious. Some states classify felonies 1st degree, 2nd degree, etc. Some states assign letters to the different classifications of felonies - E, D, C, B, and A, with A being the most serious crime.
Committing a felony can have long-term consequences far beyond the term of the sentence received. In many states, convicted felons can lose their right to vote, to acquire professional licenses, to purchase firearms, or to serve in the military or serve on a jury.