Can i use a webcam like a security camera?

The answer is YES! There is many software to use with a webcam as a security camera. Altough it is quite simple to install, it's not really discrete. Depends on what you want to do with the cam. Remember to check for the quality you require. Some webcams are not that efficient on getting clear images. There is some good softwares or freewares to try, but generally you have to buy them after a certain time for under 100$. Try inserting "Webcam monitoring" in google, and you will have a good overview of the softwares available.