What is 'module' in the Apache2 source code?

Question

Take this line for example from mod_lbmethod_bybusyness.c:

module AP_MODULE_DECLARE_DATA lbmethod_bybusyness_module;

I don't know of a module keyword in C, what is this?

Answer 1

There is no module keyword in C. It seems to be a typedef made in the projet (see http_config.h).