A private army refers to a military force that is owned and controlled by an individual or a group rather than a government or a state. There are several synonyms for the term "private army", including mercenary force, paramilitary group, militia, guerrilla army, and security company. The term mercenary force denotes a group of soldiers who are hired for a particular mission. A paramilitary group is a military group that operates in a similar manner to an official military, but it is not officially recognized or sanctioned by any government. A militia is a loosely organized group of citizens who are trained in military tactics and are often called upon to defend their community. A guerrilla army operates in a similar way as a militia but is typically associated with irregular warfare tactics. Finally, a security company is a private military organization that provides security services to clients such as private individuals, businesses, or organizations.