Entity–relationship model

An entity–relationship model (ER model) is like a map that helps you understand how different things in life connect with each other. It’s like a diagram of all of the different pieces of information that are related to one another. For example, if you have a map of all the people in a school, then you can see how they’re all connected - what classes they take together, which clubs they’re in, who their friends are, and so on. ER models help us figure out what types of information we need to store and how different things are related to each other, this makes it easier to design a database or a computer system that stores information.