CRUD (Create, Read, Update, Delete)

Definition

The four basic things you can do with stored information: create new items, read existing ones, update them, and delete them. Almost every app you use is built around these four actions, even when they're hidden behind fancier names.

More from Backend & APIs

• Authentication vs Authorization

  Authentication answers 'who are you?': proving your identity, usually by logging in. Authorization answers 'what are you allowed to do?': checking whether your account has permission to take a certain action. Both have to pass before sensitive things happen.

• CORS (Cross-Origin Resource Sharing)

  A safety rule built into web browsers. By default, a website at one address isn't allowed to grab data from a website at a different address. CORS is the way the second site can say 'it's okay, I trust this other site to read my data.' If the permission isn't there, the browser blocks the request.

• Endpoint

  A specific address on a server that does one particular thing when an app talks to it. Each endpoint is like one phone extension at a company: dial it, and you get the person who handles that one task.

• GraphQL

  A way of asking a server for data where the app says exactly what it wants, no more, no less, in a single request. Instead of getting a fixed bundle of information, the app picks the precise fields it needs, like ordering off a custom menu.

• HTTP Methods

  The little verbs that go with every request a browser or app sends to a server. They tell the server what kind of action is happening: GET means 'just give me this thing,' POST means 'create something new,' PUT or PATCH means 'change something,' and DELETE means 'remove it.'

• Idempotency

  A safety property that means doing the same action twice has the same effect as doing it once. It matters when networks are flaky and the app might accidentally repeat a request: without idempotency, you might end up charged twice for the same thing.