PMQs sees the prime minister face a grilling from MPs on both sides of the House of Commons.
Each Wednesday that the Commons is sitting, a number of MPs are selected to ask the prime minister a question about an issue they think is important to their constituents.
The leader of the opposition gets to ask a series of questions - and this is where the debate can occasionally get quite fiery.
Watching sessions take place in the Houses of Parliament can often be a baffling experience.
Names are not be used, unless by the Speaker, while calls of 'hear hear' are used to signal approval, rather than a round of applause.
But there is another strange thing that takes place during Prime Minister's Questions, and you may be wondering what it means.
At the end of a question, before the prime minister gives an answer, a number of backbench MPs may stand up and then immediately sit back down again.
This is a signal to the Speaker that they want to ask a question.
Before each session, MPs must enter their names on the Order Paper if they want to ask a question.
The list of MPs with questions is then prepared in advance and the Speaker calls them forward when it is their turn.
However, the Speaker may allow supplementary questions to be asked - and if an MP wants to ask one, they have to catch the Soeajker's eye.
They do this by standing up to signal that they have a question to ask.
The Speaker does not always allow supplementary questions to be asked, as they usually have a strict schedule to keep to.
