Roku allows you to stream movies and TV shows. There is some free content, but most of the apps require a membership that you have to pay for, ex. Netflix, Hulu, SlingTV. Streaming is shows (TV and movies) on demand, meaning you can watch them whenever you want, unlike TV where you have to be watching when it airs. The Roku channel has free movies available and there are a few other apps like PBS that you can access free shows on. You do not have to pay for service for the Roku itself, but you must have WiFi to use it.