Protective security units typically provide policing, security, intelligence and bodyguard services for Sovereigns and Politicians. They can be contrasted with security services which provide protective security intelligence (such as the Security Service (MI5); and Guards Regiments for the defence of the Sovereign and the metropolis. Examples of these include the Household Division.

There are also distinct non-combat personal bodyguards which serve as ceremonial guards and personal attendants (such as the Gentlemen at Arms, the Yeomen of the Guard, the Royal Company of Archers, and the Company of Pikemen and Musketeers of the Honourable Artillery Company, as well as the Corps of Serjeants at Arms, the Gold Stick and Silver Stick, and the High Constables and Guard of Honour of the Palace of Holyroodhouse).

Well-known examples include the Royalty and Diplomatic Protection Department of the London Metropolitan Police, and the United States Secret Service. Typically they provide security and ceremonial effect is not per se an object.