The method for using a computer's built-in webcam depends on the computer type and how you want to use it. In most cases, you need to launch a program such as a video chatting tool or movie recording application and follow the on-screen instructions to initiate recording or video transmission.
Most computers with built-in webcams come with a video chatting or recording program that automatically activates the camera and gives you the option to record footage as necessary. To record yourself on a Mac webcam, open a program such as iMovies, and select the Import button on the toolbar, then select the camera from the list of options. Choose the event that you want to house the footage, and press the Record button.
Third party programs such as Skype are compatible with both Windows and Mac webcams and usually don't require you to download any special drivers, which are updates of the operating system that enable the device to communicate with the program. Each type of operating system also comes with its own video chatting program, either FaceTime for Macs or Windows Live Messenger for Windows. In all cases, you need to open the program, log into the program's designated account and choose from your contacts to begin a video chat. All programs activate the camera automatically for video chats.