Why is there a web process active even if Safari isn't opened? I noticed that even when Safari is closed, many web processes are active, and these processes are active even when I just restarted my Mac.  

Actually, I noticed that this process is in the Spotlight web content group, what is the purpose of it and when will it stop ?
I noticed that too, and did the following to "solve the problem" (it's not a problem for some people though :P ):

In System Preferences, open Spotlight. In Search Results tab, disable Bookmarks &amp; History. Then restart. After that, Safari Web Content process won't be active when Safari is not open.