Espionage or spying, is the act of obtaining secret or confidential information without the permission of the holder of the information. Spies help agencies uncover secret information. Any individual or spy ring (a cooperating group of spies), in the service of a government, company or independent operation, can commit espionage. The practice is clandestine, as it is by definition unwelcome and in many cases illegal and punishable by law. Espionage is a method of "intelligence" gathering which includes information gathering from public sources.
Espionage is often part of an institutional effort by a government or commercial concern. However, the term tends to be associated with state spying on potential or actual enemies for military purposes. Spying involving corporations is known as industrial espionage.
One of the most effective ways to gather data and information about the enemy (or potential enemy) is by infiltrating the enemy's ranks. This is the job of the spy (espionage agent). Spies can return information concerning the size and strength of enemy forces. They can also find dissidents within the enemy's forces and influence them to defect. In times of crisis, spies steal technology and sabotage the enemy in various ways. Counterintelligence is the practice of thwarting enemy espionage and intelligence-gathering. Almost all nations have strict laws concerning espionage and the penalty for being caught is often severe. However, the benefits gained through espionage are often so great that most governments and many large corporations make use of it.