"The Apache2 HTTP Server is a modular program, where we can choose its functionality by including in the server a set of modules. The modules can be statically compiled into the httpd binary when the server is built. Alternatively, modules can be compiled as Dynamic Shared Objects (DSOs) that exist separately from the main httpd binary file.
"Normally enabling one particular apache DSO module will involve editing the main apache configuration file and adding a LoadModule line to enable the loading of the particular module..."