Client-side OAuth 2.0 is one of the easiest ways to authenticate a user for the
Box API. It is an open standard designed to allow users
to provide applications access to their data in other applications.If you’ve ever logged in to a website with Twitter, Facebook, or Google you’ve
most likely used OAuth 2.0.
Client-side authentication on Box has a similar flow where a user is redirected
from an application to the Box web app, required to log in, and grant the
application access to the user’s data.