Another category of devices is designed primarily for output. These devices get information from the cpu, and send it somewhere.
Printers take information from the CPU and transfer it to paper. There are a number of different printer technologies available.
Many people try to save money on a printer purchase and are disappointed. If the main reason you will use your computer is to type letters, remember that the people you write to will not see your monitor. What they will see is only what comes out of your printer. If printed documents are an important part of what you will use a computer for, consider a higher quality printer. Ink Jets are probably most appropriate for home use, and laser printers are more popular in an office setting. A dot matrix machine is fine for test printing or use on a kid's computer, but you will be disappointed with the results if you try to use it for business correspondence.
Before buying an ink jet, find out how much the ink cartridges cost, and how long they tend to last. With a laser printer, be sure to check on the cost of toner cartridges.