What are the benefits?
The very first and fundamental problem to solve before any communication via API can be established is the authorization. The OAuth 2.0 is an open standard for authorization, and anyone can implement it. The more software vendors would support the OAuth 2.0, the easier it would be for others to establish connection with each other in a secure way. It would also lower cost of next integrations development.
OAuth is a standard that apps can use to provide client applications with “secure delegated access”. It works over HTTPS and authorizes devices, APIs, servers, and applications with access tokens rather than credentials. It can be used to authorize single users or the whole application.
It enables apps to obtain limited access (scopes) to a user’s data without giving away a user’s password. It decouples authentication from authorization and supports multiple use cases addressing different device capabilities.
You can think of this like hotel key cards, but for apps. If you have a hotel key card, you can get access to your room. How do you get a hotel key card? You have to do an authentication process at the front desk to get it. After authenticating and obtaining the key card, you can access resources across the hotel (authorize yourself).
By implementing OAuth2 you can also allow your users/software admins to have better control over the resources shared with another software. They can see all applications which have access to those resources and revoke this access if necessary.
How to implement?
Please follow OAuth 2.0 official documentation. There are also lots of other resources on the Internet.