Databases

A database stores data so it survives after a program stops running, and so it can be searched, filtered, and updated reliably — even with many people using the same data at once.

Real-world analogy: a program's variables are like notes on a whiteboard — gone the moment you erase the board (the program stops). A database is a filing cabinet — the information stays, organized, long after you walk away.

Most databases organize data into tables of rows and columns (much like a spreadsheet) and are queried with SQL, a language built specifically for asking questions of stored data.