OAuth Grant Types are different ways you can get access token for your own Passolution account or on behalf of a Passolution user. They have different limitations and use cases which are explained below.
This is the most widely used grant type for applications that require delegated access (access on a user's behalf) and have its own servers that can directly interact with our Authorization Server (web.passolution.eu) to get access tokens.
This grant type is used when you don't have your own servers that can securely store your OAuth Client Secret & user's access tokens but still need delegated access on Passolution user's behalf.
For example, if you have a Single Page App without backend servers, you can get access token with this grant type and store the access token for user in their browser itself (Web Storage API).
This grant type can be used to get access token for your own Passolution account only. Kindly note that this grant type does not provide access on other Passolution user's behalf.