Scripts in the context of computing are usually referring to the use of basic programs or subroutines to make repetitive tasks easier. They may also refer to adding new functionality as a "Plugin"
In the realm of computer graphics, we often use scripts to automate repetitive tasks. One may use a python script to say dynamically resize a bunch of images to fit within a certain size or aspect ratio, instead of having to manually do this for each one.
When building a DXF layout for CAM or Machining from a sketchup fil, a script could be used to automatically layout all the parts flat, instead of the user having to do this manually for each part every time an update should occur.