In ordinary language, the term crime denotes an unlawful act punishable by a state. The term crime does not, in modern criminal law, have any simple and universally accepted definition, though statutory definitions have been provided for certain purposes. The most popular view is that crime is a category created by law (i.e. something is a crime if applicable law says that it is). One proposed definition is that a crime, also called an offence or a criminal offence, is an act harmful not only to some individual, but also to the community or the state (a public wrong). Such acts are forbidden and punishable by law.
The idea that acts like murder, rape and theft are prohibited exists all around the world. What precisely is a criminal offence is defined by criminal law of each country. While many have a catalogue of crimes called the criminal code, in some common law countries no such comprehensive statute exists.
The state (government) has the power to severely restrict one's liberty for committing a crime. Therefore, in modern societies, a criminal procedure must be adhered to during the investigation and trial. Only if found guilty, the offender may be sentenced to punishment such as community sentence, imprisonment, life imprisonment or, in some jurisdictions, even death.
To be classified as a crime, the act of doing something bad (actus reus) must be usually accompanied by the intention to do something bad (mens rea), with certain exceptions (strict liability).
While every crime violates the law, not every violation of the law counts as a crime. Breaches of private law (torts and breaches of contract) are not automatically punished by the state, but can be enforced through civil procedure.