Can ruby manipulate and work with peripherals like webcams? I would like to create a system that uses a webcam. Is it possible to do with ruby?
Ruby is a generally used on the server-side. As such, if you're looking for a solution to interface with a client's webcam from Ruby running on a webserver then the answer is no.
On the other hand, if you'd like to interact with a webcam connected to the server executing Ruby code (or just to execute Ruby code locally) then the answer is potentially yes. I'm not a Ruby programmer but as far as I know while Ruby most probably doesn't have direct support for talking to a webcam, it does support bindings as C-style dlls and you should be able to craft a binding for it to provide an interface for interacting with webcams.
I don't know if such bindings already exist but in case they don't you should be able to build yourself one assuming you know C/C++ or some other language that can export bindings for Ruby.