Three common print technologies are normally classified into the impact printer category: Band, Line Matrix, and Serial Matrix. While there are similarities between these technologies, there are significant differences.
 Band Printers
Band printers are closely related to typewriters in that they print by impact with fully formed embossed characters. This approach prohibits band printers from printing graphical output or varying the size of the character, and, as a result, they are rarely used.
Line Matrix Printers
 Line matrix printers form characters by impact printing dot patterns. They print dot arrays for characters by moving the paper vertically () past a hammer bank, which shuttles back and forth horizontally («) across a small space. The hammers in the bank cover the full line width, which creates portions of each character with each motion. As the paper moves upward, the print head progressively builds these rows of dots from the top to the bottom until the character(s) have been formed. The cycle is repeated until the document is printed. Line matrix printers are superior to both band and serial matrix, and their print mechanisms are far more reliable.
Line matrix printers use inexpensive ribbons and are great for long, unattended print runs. They are commonly used to print MIS reports, labels, shipping tickets, invoices, and production tags. They are well suited to printing in harsh environments such as factories and loading docks. They can also print on a very broad range of materials and make multiple copies at one pass.
Serial Matrix Printers
 Serial matrix printers also form characters by impact printing dot patterns. They have a moveable print head that has an array of pins. The print head moves horizontally («) across the paper and prints characters — one at a time — to complete the line. The paper then advances and characters are again printed horizontally across the page. The cycle is repeated until the document is printed.
Serial matrix printers come in two basic types:
 Single form/track: The single form/track can handle only one type of form. In the event you need to print a variety of reports, all using different forms, you either need to change out the form you're using now or purchase multiple serial matrix printers each loaded with a different form.
 Multiple form/track: The multiple form/track can handle multiple forms at one time. Unlike the single form/track, a multiple form/track printer can be loaded with three different forms, all of which are controlled by a push of a button or a software command. Multiple form/track saves space and eliminates the need to use multiple communication ports on one computer.
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