Server-side programs generally take input from a web browser and use that input to determine what to send back to the browser. For example, with Google Maps, the input might be coordinates on a map, and the output of the server-side program would be a new map. With the Ta-da List To Do list, the input might be a new To Do item to save and the output might be a message saying whether or not the new item was successfully saved.
Input can be sent to a server-side program as part of a
GET request or as part of a
POST request. A
GET request is used when the input you are sending to a server-side program is fairly short, such as sending a coordinate to Google Maps to be mapped. A
POST request is typically ...