In the design world, there are two types of images: Raster and Vector. Confusing them is the #1 reason for amateur-looking logos.
Raster (PNG, JPG, GIF)
These images are grids of colored pixels. Imagine a mosaic tile floor. It looks great from a distance, but if you get close, you see the blocks.
Problem: You cannot resize them up. If you stretch a 100px PNG to fill a billboard, it looks blocky.
Vector (SVG, EPS, AI)
Vectors are not pixels. They are mathematical instructions. An SVG file says "Draw a circle with radius 5, color red."
Superpower: Infinite scalability. You can print an SVG on a business card or the side of a jumbo jet, and the curve will be perfectly smooth. The file size stays tiny.
When to use what?
- Use SVG for: Logos, icons, charts, illustrations.
- Use PNG for: Photos, complex artwork with shadows/textures, screenshots.