The video clips we have just watched have demonstrated different types of register, that is, formal and informal register.

Formal register is used for official purposes while informal register is used among friends or peers.

It is important that appropriate register be used in all contexts in order to communicate effectively.

Note that, in some contexts, certain words and behaviour are  expected.

For example, it is possible to tell that the lawyer and the judge are having a courtroom conversation because of their behaviour and choice of words