Workgroup switch, or router?

Question

ok, what i have is a pc, a laser printer, and a cable modem.

can i use a workgroup switch so that i can use the modem and printer at the same time, or do i need a router?

Answer 1

is the printer ethernet? or is it USB? If it's ethernet then you need a router. if it's USB then you don't need anything

Answer 2

There are a few ways you can configure this set of 3 items.

PC to the Cable Modem.   Printer to the PC.  Is one of the most common.

Another would be Router to PC.  Router to Printer.  Cable Modem to Router.

Yet another would be Cable Modem to PC.  PC to Switch. Printer to Switch.

You can use a switch but, it won't allow for future expansion like a Router will.   Today you have 3 devices.  Next year you may have 7.  

I would recommend you get a decent wireless router. $119 or so for a D-Link DIR-655.  Comes with 4 Gigabit ports built in.

Offers wireless of the 802.11 draft 2.0 N variety.