How do i know what has changed from apache 2.2 to apache 2.4?

[giraffelife]

In this particular article it is just best to point you to the apache links directly. As they have made it clear to follow.

Some of the major changes
https://httpd.apache.org/docs/2.4/new_features_2_4.html

Upgrading to 2.4 from 2.2
https://httpd.apache.org/docs/2.4/upgrading.html

List of all apache 2.4 configuration directives
https://httpd.apache.org/docs/2.4/mod/directives.html