---
id: overview
title: Overview
---

Authentication Providers in **NextAuth.js** are services that can be used to sign in a user.

There are four ways a user can be signed in:

- [Using a built-in OAuth Provider](/configuration/providers/oauth) (e.g Github, Twitter, Google, etc...)
- [Using a custom OAuth Provider](/configuration/providers/oauth#using-a-custom-provider)
- [Using Email](/configuration/providers/email)
- [Using Credentials](/configuration/providers/credentials)

:::note
NextAuth.js is designed to work with any OAuth service, it supports **OAuth 1.0**, **1.0A**, **2.0** and **OpenID Connect (OIDC)** and has built-in support for most popular sign-in services.
:::
