The script is the document that 'tells the story' of what is to happen and how it is to happen, by whom (the actors), where (the locations), how (the props, lighting and technologies).
For all involved in the production it is the running sheet of everything. See the example script below, which details:
The timing.
Each scene.
What is being said.


Though the script can be changed 'on the fly' (during the rehearsals) to allow for adjustments to improve the video. This can be in the flow of the performance, or technicalities.