How is MI5 different from MI6?

Note: This search is prompted by my exploration of the so-called Deep State -- the behind-the-scenes effects of how the US, Britain, Israel and other countries impact the political, economic, social and military effects that shape our lives.

The primary difference between MI5 and MI6 is their geographic jurisdiction: MI5 handles domestic security and counterintelligence within the UK (similar to the FBI), while MI6 operates globally to gather foreign intelligence and conduct covert operations (similar to the CIA). [1]

MI5 (The Security Service)

Role: Protects the UK against national security threats at home, including terrorism, espionage, and sabotage.
Headquarters: Thames House in London.
Leadership: Answers to the UK's Home Secretary. [1, 2, 3, 4]

MI6 (The Secret Intelligence Service - SIS)

Role: Gathers overseas human intelligence and executes covert operations to protect British interests worldwide.
Headquarters: Vauxhall Cross in London.
Leadership: Answers to the UK's Foreign Secretary. [1, 2, 3, 4, 5]

Both agencies trace their roots to the Directorate of Military Intelligence (hence the "MI" prefix) from World War I, but they are now fully civilian organizations operating independently of the armed forces. [1]