Thermal paper is a specialty paper that changes color when subjected to heat, without the use of traditional ink. This effect is achieved by coating the paper with heat-sensitive dyes and developers during the manufacturing process. You can check this Infographic to have a complete understanding of what thermal paper is and how it works.
A thermal print head consists of a multitude of miniature heating elements distributed along its printing width. It is commonly used to produce receipts in Point Of Sale (POS) printers, ATMs, cash registers and EFTPOS terminals.