Continuity in film

Continuity is used to keep the audiences attention on what is happening and not to break that:

180 degree rule - The 180 degree rule establishes where the characters are within the 180 degrees that you can film them from because if you were to film on the other side, the characters would have flipped sides and the audience would be able to see all the other things in the background as it is a new background. This would therefore confuse the audience and break continuity.

Shot-reverse shot - When you keep the same line when filming and you switch the shot between the two characters during a conversation, this used with the 180 degree rule allows the audience to clearly understand what positions the characters are in.

Match on action - When you cut the shot mid-action to a different angle so it doesn't look unnatural and the audience don't notice it as the shots switch seamlessly, for example match on action is used when someone is sitting down.