ELI5: raster vs vector

What is raster vs vector?

Raster images are like a giant checkerboard where each tiny square has a color—kind of like a picture made of LEGO blocks [1][3]. Vector images are made of invisible instructions that tell the computer to draw lines and shapes, like a connect-the-dots drawing [2][5].

Why do they look different when you zoom in?

When you zoom into a raster image, you start seeing all those colored squares (called pixels) and it gets blurry [2]. But vector images stay perfectly sharp no matter how big you make them, because the computer just redraws the lines bigger [2].

Which one takes up more space?

Raster images need to remember the color of millions and millions of tiny pixels, so they're much bigger files [1]. Vector images just need to remember a few instructions like "draw a line from here to there," so they're smaller [5].

When do you use each one?

Use raster for paintings, photos, and detailed drawings because they can show tons of tiny details [4]. Use vector for logos, signs, and designs that need to print big and stay crispy-sharp [4].