Output devices are used for extracting processed values from a computer. computer output in various forms, the modern computer systems apart from using amonitor display and printed paper use a variety of other devices such as plotters,speakers,microfilm recoarders & speech synthesizers.
printers are primary output devices used to prepare a permanent document for use printers are classified with regard to haw they print and how they print and how fast they operate.

1)Daisy wheel printers use a metal or plastic disk with characters embossed along the edge, the disk rotates until the required character is brought before a hammer which strikes it against a ribbon. the quality of the characters is very good. it can print 8 to 50 cps. cps full form c-characters ,p-per,s-second.

2)Dot matrix printers print characters with a series of closely spaced dots, these printers are ost widely used. the letter quality is not as good as that of daisy whel printers. the speed ranges from 180 to 400 cps.

3)The line printer has speed of 600 to 2000 lpm.l- lines,p-per,m-minute. instead of priniting one character st a time these printers print 1line.

4) A laser printer is used when better quality printing and very high speed is needed you can change the fonts ,characters styles. and the size of the characters.
In this type of printer the character are drawn by the computer using laser beams the dots are cloelsy packed to give the maximum clarity.laser printers are mostly used for DTP work.