A behavioral or social script is a series of behaviors, actions, and consequences that are expected in a particular situation or environment. Just like a movie script we know what to expect in many social settings. Individuals learn from past experiences and use these expectations to build scripts that make things easier for us cognitively.
An example can be seen when you go to the grocery store. You park, get a cart, walk down the aisles getting what you need, you check out, take your groceries to the car, load them, return the cart, and drive away. This is a typical and expected scenario to encounter when you go to the store and is a behavioral script that has been developed and fine tuned over time.