A more thorough explanation:

The term illegal refers to any action that goes against the law or is not authorized by it. It can also be called illicit or unlawful. This can include actions that violate criminal law, such as assault, arson, or murder. These actions are considered felonies or misdemeanors, depending on the severity of the crime. However, not all illegal actions are punishable under criminal law. Some actions may violate public policy or civil legal obligations, but not be recognized as criminal offenses.

• Robbing a bank is illegal and is considered a felony under criminal law.
• Driving without a license is illegal, but it is usually considered a misdemeanor offense.
• Breaking a contract is illegal, but it is not a criminal offense. Instead, it is a civil matter that can be resolved in court.

These examples illustrate how illegal actions can vary in severity and consequences. Robbing a bank is a serious crime that can result in a long prison sentence, while driving without a license may only result in a fine. Breaking a contract may not have any criminal consequences, but it can still result in financial penalties or damages.