Criminal offenses under state and federal laws are generally categorized by the seriousness of the crime as felonies (more serious) or misdemeanors (less serious). Felonies are offenses that generally may result in prison sentences of more than one year, and misdemeanors carry sentences of one year or less. The United States Congress sets the penalties for all federal criminal offenses, and thus decides which criminal offenses are felonies and which are misdemeanors. And the state legislature in each state decides which criminal offenses are felonies and which are misdemeanors under state law.

In Connecticut (CT), criminal offenses are classified into felonies and misdemeanors based on the severity of the crime, consistent with the broader distinction used across the United States. Felonies in Connecticut are serious crimes that can result in imprisonment for more than one year, and they are further divided into classes (Class A, B, C, D, and unclassified felonies) with Class A being the most serious. Misdemeanors in Connecticut are less serious offenses and are also divided into classes (Class A, B, C, D, and unclassified misdemeanors), with Class A misdemeanors being the most serious within this category, carrying a maximum sentence of one year in jail. The Connecticut General Assembly, the state's legislative body, determines the classification of state offenses and the corresponding penalties. For federal offenses, the United States Congress establishes the classifications and penalties, determining which offenses are felonies and misdemeanors at the federal level.