Read this and answer the question

The role and functions of the CIA are roughly equivalent to those of the United Kingdom's Secret Intelligence Service (the SIS or MI6), the Australian Secret Intelligence Service (ASIS), the Egyptian General Intelligence Service, the Russian Foreign Intelligence Service (Sluzhba Vneshney Razvedki) (SVR), the Indian Research and Analysis Wing (RAW), the Pakistani Inter-Services Intelligence (ISI), the French foreign intelligence service Direction Générale de la Sécurité Extérieure (DGSE) and Israel's Mossad. While the preceding agencies both collect and analyze information, some like the U.S. State Department's Bureau of Intelligence and Research are purely analytical agencies.[citation needed]

What is the UK's equivalent to the CIA?
Secret Intelligence Service