The director and the director of photography in a film set are the ones that are responsible for where the camera is placed. This is probably the most powerful decision that they make, the most boring thing they can do is just set the camera up and start recording. They generally don't do that, they put the camera in two interesting positions to try to create a meaning.
Establishing Shot.
The purpose is to show the setting, the camera's usually a long way away from what's actually being filmed, to establish where we are, what we're looking at and what the setting is.
Long Shot.
Little bit closer than establishing shot, shows the entire body of the actor and often a lot of the surrounding environment. The reason it is used is to try put the character in a setting.
Full Shot.
It shows the full body of the actor, trying to show the entire character, showing the costume, what sort of body type they have or what sort of stance they're using. This one keeps the audience out of distance.
Mid-Shot.
It shows the top half or half of the actor, mid between long shot and close-up. Closer to the actor.
Close-Up.
Focuses on just one part of the body, usually face because we're trying to engage, feel deeply and intimately connected to them. .
Extreme Close-Up.
Focuses on a part of the body such as eyes, finger or ear, usually used to stress something really important about that part of the body, probably feel uncomfortable.
Camera Angles.
Eye-Level - how we tend to look at people unless they are taller or shorter than us. Suggesting Equality.
Low-Angle .
Low and High {where the camera is placed}, force to look up, makes the subject lot more powerful. Makes them seem bigger, dominant, audience less powerful.
High-Angle .
Exact reverse on a high position, looking down on characters which makes them seem smaller and weaker.
Overhead Shot.
Similar to a establishing shot, might be suggesting where people are in the environment.
Undershot.