How does spring boot authorisation and authentication work

Question

I took over my current project from my colleague. And he is using Spring Boot. Now I wonder how login and Roles work. All I can see is namely this.

@Configuration
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    Environment env;

    @Override
    public void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
                .antMatchers("/api/tester/**").hasAnyRole("TESTER", "AUTHOR", "ADMIN")
                .antMatchers("/api/author/**").hasAnyRole("AUTHOR", "ADMIN")
                .antMatchers("/api/admin/**").hasRole("ADMIN")
                .anyRequest().fullyAuthenticated()
                .and().
                formLogin();
    }

In the database there is a authorities table with a column authority. It seems Spring boot knows this and goes there. Also I found a login.html . It looks like also Spring Boot uses this automatically and provides appropriate attribute object ${param} . Also I cannot find a controller. URL to login is simply /login . If you were not using a framework then on every page you would need to check if user is currently logged in and has appropriate Role. So in user table you would have a column loggedIn and if loggedIn then you would set it to true. I suppose.