The Royal Air Force's go-to weapon – the Paveway IV guided bomb – has been in operational use since 2008.
Paveway IV is an advanced and highly accurate weapon that has been used on operations in Libya and against the so-called Islamic State (IS) in Iraq and Syria.
The state-of-the-art precision-guided bomb can service the vast majority of the RAF's potential targets sets, making it the "overwhelmingly dominant strike weapon", according to air power expert Justin Bronk.
Costing about £30,000 each and weighing 226kg, the Paveway has four main parts – the guidance system in the front, a 500lb warhead in the middle (which can penetrate concrete) and, at the back, the tail section guides the bomb, with a smart fuse to control how it detonates.
GPS is one way the bomb can be guided to its target.
When the weapon is released the aircraft gives it target co-ordinates based on its own concept of where it is, and it is able to interface with the signal from GPS satellites and, therefore, fly itself to a very accurate grid reference.
The Paveway IV is what is called a dual-mode weapon so it can also be guided onto its target using a laser.
A laser beam with a code will be fired and the weapon will look for the reflected energy of that laser spot – which is being projected onto the target – and will home in on that.
Typhoons dropped Paveway IV over Iraq last month in support of Iraqi ground forces coming under fire from IS fighters, about 30 miles from Erbil, northern Iraq.
Paveway IVs are going to be fitted onto the UK's new F-35 Lightnings – in stealth mode, they will carry them internally in the jets bomb bay – a tried-and-tested munition that is the backbone of the RAF's arsenal.
Watch: Typhoons attack so-called Islamic State in Iraq with Paveway bombs.