As one of the most advanced aircraft in the world, the Lockheed Martin® F-35B® Lightning® is a fifth generation multi-role combat aircraft designed to dominate the skies, using stealth technologies to operate undetected in hostile airspace, striking at the heart of the enemy, or relaying vital battlefield information to other friendly forces. 
The United Kingdom has elected to take the short take-off and vertical landing (STOVL) "B" variant of the F-35, allowing their aircraft to operate from traditional airfields, from the decks of Britain’s two new Queen Elizabeth class aircraft carriers and should the need arise, from dispersed locations, in much the same way as the famous Harrier previously did. 
In British service, the F-35 will not carry the Lightning II denotation, as the new jet is actually the third aircraft in RAF service to carry the name, after the Lockheed P-38 from the Second World War and the famous English Electric Lightning which served throughout the Cold War era.