For the curious: https://en.wikipedia.org/wiki/List_of_intelligence_gathering_disciplines https://en.wikipedia.org/wiki/List_of_intelligence_gathering... The b

For the curious: https://en.wikipedia.org/wiki/List_of_intelligence_gathering_disciplines https://en.wikipedia.org/wiki/List_of_intelligence_gathering... The big ones are HUMINT, GEOINT, MASINT, OSINT, AND SIGINT. In the US the responsibility typically falls like this: CIA = HUMINT & OSINT NSA = SIGINT & MASINT NRO / NGA = GEOINT (& probably some MASINT) edit: A lad below me has a better (and more complete) answer.