1.Register is defined as the level of formality in language that's determined by the context in which it is spoken or written. It can be formal or informal. Formal speech is proper, while informal speech is conversational or casual.
2.The informal register (also called casual or intimate) is conversational and appropriate when writing to friends and people you know very well. The neutral register is non-emotional and sticks to facts. It is most appropriate for technical writings.
