UsernamePasswordAuthenticationFilter – Looks for the username and password in the request and tries to authenticate if found these parameters in the request.

SecurityContextPersistenceFilter – Populates the SecurityContextHolder with information got from the configured.

ConcurrentSessionFilter – Filter for handling concurrent session.

DefaultLoginPageGeneratingFilter –Generates a login page for you, if you don’t explicitly disable that feature.

addFilter: This adds a custom Spring Security filter anywhere in the filter chain

addFilterBefore: This adds a custom filter before an existing specified filter class in the chain

addFilterAfter: This adds a custom filter after an existing specified filter class in the chain

addFilterAt: This adds a custom filter at the location of an existing specified filter class in the chain 

https://www.javadevjournal.com/spring-security/registration-with-spring-security/