Clandestine professionals engaging in espionage and covert OPS require a particular way of thinking and feeling, a dynamic psyche.
Deep dive into the double agent; personnel that engages clandestine moves for more than one opposing security service or intelligence agency.
Industrial espionage is the clandestine act of illicitly acquiring corporate intel and trade secrets from a group to be used for another group.
Spying on a person or group to illicitly acquire intel to be used against them or to be used advantageously for the operative and or sponsor.
Spies usually come in two main types: those that gather intelligence themselves and those who recruit others to gather information for them.