To pixelate means to break an image into visible square blocks called pixels, making it look blocky and unclear. When a photo is pixelated, you see chunky squares instead of smooth details. You've probably seen this when someone zooms way in on a digital photo: a person's face might turn into a jumble of colored squares where you can barely make out their features.

Pixelation happens for different reasons. Sometimes an image starts with too few pixels to look sharp, like when you try to print a tiny website picture on a large poster. Other times, TV shows or news programs deliberately pixelate faces to hide someone's identity, or pixelate license plates to protect privacy. Video games from the 1980s and early 1990s looked naturally pixelated because computers back then couldn't handle as many pixels, which is why old game characters look so blocky compared to today's smooth graphics.

When pixels become large enough to see individually, the image is pixelated. Modern cameras use millions of pixels to create sharp photos, but if you keep enlarging any digital image enough, it will eventually pixelate.