A photocopier is a machine that makes exact paper copies of documents by using light and electric charges. When you place a page on the glass surface and press a button, the photocopier scans the original with bright light, converts the image into electrical signals, and prints duplicate copies on blank paper, usually within seconds.

Before photocopiers became common in the 1960s, making copies was slow and messy. People used carbon paper (which left smudgy blue marks on your fingers) or had to retype entire documents. The photocopier revolutionized offices, schools, and libraries by making it easy to share information. Today, teachers use photocopiers to make classroom handouts, offices copy important contracts, and libraries help students reproduce research materials.

The technology works through a process called xerography, which uses static electricity to attract powdered ink (called toner) onto paper. Modern photocopiers often combine copying with printing and scanning, which is why they're sometimes called multifunction machines.

You might hear someone say they need to “make a photocopy” or “run something through the copier.” Many people simply say “copy” as a verb: “Could you copy this article for me?”