Keycloak Secure any application

In life, there are many problems posed to the software industry . But most of the software that we create has a security and decentralization mechanism and user management.

So what can keycloak do in the above problems?

Add Authentication and Authorization to your system.

Add UserManagerment to your system.

Add Single-Sign-on and Single-Sign-out to your system.

Add Permission(Role-User) to your system.

Can be used for most types of software deployment models(microservice-monolithic) For ease of visualization I drew it with MONOLITHIC before the keycloak After : So what happens when we use the MICROSERVICE ?