More Film Terminology

Wipe
An editing technique in which images from one shot are fully replaced by the images of another, delimited by a definite border that moves across or around the frame

Another Wright technique which I actually guessed right in my Hot Fuzz post (although didn't explain QUITE as well as IMDB).

Racking Focus
A shift in focus between planes at different distances from the camera within the same shot.

I know what these shots are and I would recognise them but I would really like to learn how exactly to do them because I find it hard enough to focus with a normal camera to take a simple photograph.

Reverse Shot
AKA: Reverse Angle, Hollywood Reverse
A shot taken at a 120-180 degree angle from the preceding shot. When used in dialogue scenes, reverse-shot editing usually alternates between over-the-shoulder shots that show each character speaking. See also shot/reverse shot.

I have seen these kind of shots in practically every film I've watched. In the first conversation scene in Hot Fuzz this technique is used but between lots of other techniques to make it more interesting and have a bit of variety.