Can you use a digital camera for a web cam?

Some digital cameras will work as a web cam. Some won't. Newer digital cameras have the necessary computer interface to act in that capacity. It's best to check the manufacturer's web site and the online product specs to see if a particular digi cam will work as a web cam.

no.

Yes, you can use the Digital camera/Camcorder for that purpose. They should support USB streaming. Many Sony cameras support that. I know that Panasonic and Canon support that. Check the individual camera's manual.

Some cameras offer this option. Mine doesen't, so check your owner's manual or talk to somebody at the store you want to buy it at.

Good Luck!

No... webcams are special to Windows XP as they appear as web cameras. Digital cameras are in the Digital Imaging category and thus cannot appear to Windows as a web cam.

Also, web cams are built differently than digital cameras... they are always "live" if they are plugged in... digital cameras are not.

Erased Paper is right, some offer a hybrid option. Check your user manual.