Auth method for Azure AD? Azure AD or OIDC? Difference?

I want me and my colleagues to authenticate to Vault using our company Azure AD accounts so we can sign our SSH keys.

I’m a bit confused, there seems to be two methods to authenticate against Azure AD.

Azure AD -

There are lost of online guides that tells you to use OIDC…is because Azure AD plugin didn’t exist yet or that Azure AD is compatible with OIDC anyway?

I’m just trying to figure out the best and most easy method so my users can authenticate to Azure AD.

By the looks of it, both Azure AD and OIDCS needs an app registration in azure for Vault.

All authentications will be done using the cli tool.