I know michaelmurfy has already covered routers recently, but I need a straight yes or no answer.  Please excuse the simple/broad terms I may use.

Here we go:

Can a network switch, be used like a normal WiFi router, for just Ethernet, to provide Internet connection to my PC?  Secondly, do they all support VLAN Tagging and stuff for Fibre (e.g. will the cheapest one from PB Tech work)?

I know I'm using simpleton language, and that this may seem like a stupid question; but please, I need to know.  Once this has been answered, there need not be any other replies; unless the answer was wrong there is more important information to know about it.