What is a Printer?

Printers are used to produce hardcopy of computer output, normally data or text, but also in case of certain printers, graphics, that is such as drawings or charts. Printers vary in their capabilities as far as text enhancements such as underlining or emboldening are concerned and also in their ability to print graphics.

Most printers are designed to receive data in parallel from the computer, i.e., 8 bits at a time. These have to be connected to the parallel port on the computer, also called Line Printer 1 aka LPT1.

Computer printers differ in the following aspects:

• There are character printers, which print one character at a time, line printers, which print a line at a time, and page printers, which print a page at a time.
• A variety of printing technologies are possible, the main ones being dot matrix, daisy wheel, inkjet and laser.
• Some printers can only handle text whereas others can handle text and graphics.
• There are a variety of standards for control codes, which are commands, sent from the computer to the printer to turn on effects such as underlining and emboldening.

However, most software packages are able to cope with these differences. They do so by means of pointer drivers, specials programs that adapt the output from the software to the printer. All you have to do is select your printer’s name from the list that is presented to you when you first use the software.

The main types of printers are described below. The main differences between the printers depend on:

• The quality of output
• The ability to print graphics
• The printing speed