MI5 is responsible for protecting UK citizens and interests at home, notably against threats to national security. By contrast, MI6 (also referred to as the Secret Intelligence Service) is responsible for gathering intelligence outside the UK in support of the government’s foreign and defence policies.

MI5 (Military Intelligence, Section 5), [2] officially the Security Service, is the United Kingdom's domestic counter-intelligence and security agency and is part of its intelligence machinery alongside the Secret Intelligence Service (MI6), Government Communications Headquarters (GCHQ), and Defence Intelligence (DI).

Find out about the core threats to national security that MI5 exists to protect against. Discover how MI5 works to protect against threats to national security through intelligence gathering...

mi6是政府对外情报机关，mi5是政府反间谍机关。 除此以外，gchq（政府通信总部）是英国的信号情报机关。

2023年7月10日 · MI5 and MI6 are two iconic intelligence agencies of the United Kingdom. While their functions and areas of operation differ, both agencies play integral roles in safeguarding the United Kingdom from a wide range of security threats.

英国秘密情报局（Secret Intelligence Service，SIS），常被称为军情六处或军情六局（Military Intelligence, Section 6，MI6），是英国对外情报机构，主要作用是根据联合情报委员会的要求和部长们的批准，就涉及英国安全、国防、外交和经济政策等重大利益的问题提供秘密 ...

军情五处（MI5）是英国国内的反情报及国家安全部门（The Security Service），在内政大臣领导下工作，但不隶属于英国内政部，负责打击国内的严重罪案、 军事分离主义 、 恐怖主义 及间谍活动，而对外的国安职务则由 军情六处 负责。军情五处的调查人员并没有 ...

2018年4月12日 · 军情五处（MI5）是英国国内的反情报及国家安全部门（The Security Service），在内政大臣领导下工作，但不隶属于英国内政部，负责打击国内的严重罪案、军事分离主义、恐怖主义及间谍活动，而对外的国安职务则由军情六处负责。

1 天前 · MI5, the domestic security service, was led by Stella Rimington from 1992 to 1996 and Eliza Manningham-Buller between 2002 and 2007. ... Like many things about MI6, also known as the Secret Intelligence Service, the process of choosing Moore’s replacement takes place out of public view. It began with the country’s top civil servant, Cabinet ...

军情五处（MI5）的正式名称是Security Service（安全局），隶属于英国内政部，负责在英国境内和境外从事防御型反间谍工作、在英国境内从事进攻型反间谍工作、反恐怖工作等，但也可以从事策反在英国境内的外国公民这类实质上的对外情报工作：