inkjet
A printer that sprays tiny drops of ink onto paper.
An inkjet printer creates images and text by spraying tiny droplets of ink onto paper, sort of like an extremely precise spray paint can controlled by a computer. The printhead moves back and forth across the page, releasing microscopic dots of ink in different colors (usually cyan, magenta, yellow, and black) that combine to form whatever you're printing.
If you've ever watched a printer work, you've probably seen the printhead sliding left and right while the paper feeds through. Each pass lays down thousands of ink droplets, so small you'd need a microscope to see individual ones. The printer's computer brain tells it exactly where to spray each color to recreate your document or photo.
Inkjet printers became popular in homes and schools during the 1990s because they could print in color and cost less than other types of printers. They're especially good at printing photographs because they can blend colors smoothly. The main drawback? Those ink cartridges run out and need replacing, which can get expensive.
As an adjective, inkjet describes things made for or using this kind of printing, like an inkjet printer or inkjet paper.