Styles of Scripts

Theatre:

A play script is different to other forms of script such as film and TV as there is a lot more dialogue in them. Stage directions are used for crucial moments of action, for example "Margeret passes the letter to Jonathan" or "Paul is sitting DSR. Matt enters aggresively from SL" However the majority of the script is dialouge which gives the director an actors more of an opportunity to put their own interpretation onto the story. 

Playscripts also feature all of the props, set and costume needed for each scene which is used as a guide for the director, set designer, lighting designer and actors so they can get an idea for 

When a new character comes on stage for the first time, a theatre script will give lots of details on what that character is like, including looks, personality, clothes, how they speak etc. This is included to help the actor portray the character in the way that the writer intended. It may also be important for characters to look/act a certain way for parts of the story to work so it is important to include this information. 

Film:

Film scripts have a lot more detail that theatre scripts. They usually include a lot of information about the set, here is an example from "Pride": A CLASH poster above the cooker, a Soviet flag beside it partially obscured by a life size cut out of Eartha Kitt. MARK walks in, wearing boxer shorts, and switches on a crappy little portable TV. TISWAS. Lenny Henry being gunged in a cage. He switches over. A wave of policemen charging a picket line of striking miners. He switches on the kettle..." They do this because film sets are a one time thing so it is extremely important for the set designers to know as much detail as possible so they can make it as accurate as possible. Sometimes film productions hire location managers to find places to shoot in, so it is important to put lots of information in the script so that they can find the most appropriate place.

The scenes are much shorter in film scripts because the scene changes every time they move place or time. So for instance there could be a shot of one person in the front room and then a shot of someone else in the kitchen and they would be seperate scenes, whereas on stage you could have a set of a kitchen and a front room and both actors could be on stage together in the same scene. Here is a screenshot of a page from "Pride" so you can fully see how short film scenes are:

Film scripts also have heading at the start of every scene, similarly to how theatre scripts have stage directions at the start of every scene to tell you who is in the scene, where it is set and when. Film scripts also have this but layed out in a different way. You need to put if it is inside or outside, where the scene is set and what time of day. For example:
Ext. The Street. Day time.
Ext stands for outside and Int stands for inside. This is a quick way of getting a lot of information in before the scene has even started. 

TV

TV scripts are more similar to film scripts in terms of format and dialogue to description ratio. However there are some important differences. 

For example, in re occuring dramas such as Coronation Street or Eastenders, the script writers don't have to worry too much about the details of the set because it is more than likely that the sets have been the same for a very long time so the director doesn't need to know a lot about it as there is a mutual understanding of where they mean. For example if the script said "Whitney is sitting on the bench", the director would know where they meant, but in a film or even a play they would need much more detail, for example "Whitney is sitting on a black bench alone in a park near a tree."