It depends upon the type of webcam, although Linux does have good support for most webcams a few may not work "out of the box". It also depends upon what you want to do with the video and what else is running at the same time.
The Raspberry Pi camera has the advantage that it doesn't have to go via USB which adds an additional overhead.
Omar, i'd like to second Stewart's post. I've been playing around with webcams for a week or two now, and that pretty much sums up my findings so far. Three webcams, not all worked the same or at all in some cases. One thing I would say though is that they have been doing a lot of work on the firmware for the pi, and a recent update made a lot of things better. One of my better working ones is a generic model that cost less than £5 so it is worth trying as it only costs a quarter of the official Pi camera.
I also have one of the 'real' Pi cameras though and I have to say i'm quite impressed. The pi is currently mencoding a time lapse video of the view out of my back window !
Thanks for the info Ill take a look at your info and toy arround to find the best solution for me, again thanks a lot for the info its very clear and usefull it solves my questions, Ill let every one know the best solution for future reference since I have the latest Pi model up to date.
Apart from the obvious RPi camera module which works out of the box with the latest Raspian image I am using a USB Logitech C110 which cost a tenner and also works out of the box. The biggest problem with some webcams is power as there is limited power available on the USB ports so if you're running a camera and a wifi module you might struggle unless you use a powered USB port. The RPi camera module doesn't have this issue and the C110 that I am using seems to be low powered and works with a WiPi.
