unknown Background processes running in sql server

If you see sp_who2 or run the below query

select * from sysprocesses where spid<50 you can the following processes running in sql server background.

There might be more, I'll add as soon as I see the new ones;

Currently I don't have the exact description of what each process does

RESOURCE MONITOR
LAZY WRITER     - this is the one which writes the committed portion of Transaction log to disk
LOG WRITER      - this is the one which writes the transactional changes from memory to Tlog??
LOCK MONITOR   
SIGNAL HANDLER 
TASK MANAGER   
TRACE QUEUE TASK
UNKNOWN TOKEN  
BRKR TASK      
TASK MANAGER   
CHECKPOINT      - this is well known to everyone, this flushes out the data from memory to disk
BRKR EVENT HNDLR
BRKR TASK      
TASK MANAGER    

I'll try to find out the remaining and 'll post updates