Venue is the legally proper or most convenient place where a particular case should be filed or handled. Every state has rules determining the proper venue for different types of lawsuits. For civil cases, venue is usually the district or county which is the residence of a principal defendant or where they regularly conduct business, where a contract was executed or is to be performed, or where an accident took place. However, the parties may agree to a different venue for convenience (such as where most witnesses are located). Normally, the venue in a criminal case is the judicial district or county where the crime was committed. The state, county or district in which a lawsuit is filed or a hearing or trial in that action is conducted is called the forum.
For various reasons either party to a lawsuit or prosecution may move (ask) for a change of venue, which is up to the discretion of a judge in the court where the case or prosecution was originally filed. Reasons for such a request may include a clause in a contract stating that any action must be brought in a certain other venue, or pretrial publicity may be claimed to have tainted the potential jurors in that venue from rendering an impartial judgment.