REST (REpresentational State Transfer) is a architectural pattern that allows networked software systems to communicate with each other. The principle of REST emphasises consistent + uniform interfaces.
Each data resource is represented by an API endpoint. Standard HTTP requests allow interaction with this data (GET to read, POST to add a new item, PUT to replace an item with newer data, DELETE to remove).
For example,
/itemsrepresents a collection of items, and/items/<item>represents a specific item.