only print text, but later developments allowed printing of graphics. Modern printers can receive data in multiple forms like vector graphics, as an image, a program written in a page description language, or a string of characters. Multiple types of printers exist: Inkjet printers An inkjet printer injects tiny droplets onto the printing medium via a series of nozzles on a printing head. Laser printers A laser printer uses a laser to charge a drum of toner in order to mark points where the toner would stick onto the medium. Thermal printers A printer which heats up a thermally sensitive roll of paper to reveal ink. Most often seen in retail stores to print receipts. Dot matrix printer A printer which uses impact to transfer ink from a ribbon to the medium. Plotter A plotter is a type of printer used to print vector graphics. Instead of drawing pixels onto the printing medium, the plotter draws lines, which may be done with a writing implement such as a pencil or pen. Teleprinter A teleprinter or teletypewriter (TTY) is a type of printer meant for sending and receiving messages. Before displays were used to display data visually, early computers would only have a teleprinter for use to access the system console. As the operator would enter commands into its keyboard, the teleprinter would output the results onto a piece of paper. The teleprinter would ultimately be succeeded by a computer terminal, which had a display instead of a printer. Headless operation A computer can still function without an output device, as is commonly done with servers, where the primary interaction is typically over a data network. A number of protocols exist over serial ports or LAN cables to determine operational status, and to gain control over low-level configuration from a remote location without having a local display device. If the server is configured with a video output, it is often possible to connect a temporary display device for maintenance or administration purposes while the server continues to operate normally; sometimes several servers are multiplexed to a single display device though a KVM switch or equivalent. Some methods to use remote systems are: Remote access The computer's console can be accessed through a network connection such as the Internet, using protocols such as telnet or SSH. Remote desktop Allows a Graphical User Interface to be accessed through remote access even without a