Do most companies have internet access for employees at work and why?

Where I work, they only have intranet — so only work related sites only.
I heard of people surfing the net while at work.
Does your boss let you do it?
What’s your occupation and why do you need internet access.
How can you get any work done?
If you have free time to do it, how much free time do you have to do it?

as far as work concerns,i allow all my staff desktop computers to access internet everyday,at times let them play games to release their tensions of work.i m a very open-minded person as long as my company is making money.of course my staff should complete his work first before going into net,this’s the basic rule.i m doing "import n export" business n i need lots of bookings,so browsing net is very helpful n important as well.only 3-4 hours if i’ve my free time.

best wishes.