Can someone tell me the purpose and please explain their usage of the following modules? Profiler, profle customizer,  desktop, open social, page access contrl.

 here you can find the answers for some of them:

http://www.boonex.com/forums/topic/What-do-i-need-these-mods-for-.htm

ok thanks

• OpenSocial is pretty useless, and it's going to be removed in a future version.  I recommend you skip it.
• Profile Customizer is kind of like the old Myspace, where you could change the background, block styles, etc.
• Profiler is some kind of diagnostics tool, if I recall correctly.  It shouldn't be installed unless you actually need it.