How does Apache know the names of the handlers in each module?

Question

I was reading the following: http://modules.apache.org/doc/API.html

Please explain how Apache knows the name of the handler to call. The CGI Module has the following handlers:

int translate_scriptalias (request_rec *);
int type_scriptalias (request_rec *);
int cgi_handler (request_rec *);

Another module might have some other names. How does Apache know which is the handler for the (let's say) response phase ?

PS: Can someone assign the right tags ? I couldn't know which ones to attach.

Answer 1

They're (eventually) members of the module struct at the bottom of the first snippet.