This weekend, I was discussing the difference between Raster and Vector files to my family, and thought a post with images might make it easier to understand.
Raster:
Raster files are made out of dots (or pixels). I think of them like paintings by the famous pointillist Serat. You've likely seen his most famous painting, Sunday Afternoon. If you look closely at the painting, you see that the image is made entirely of dots:
But if you were to step away from the painting, as in this famous shot from the film Ferris Bueller's Day Off, the lines within the painting look ore continuous:
The same is true for Raster files. You can draw or color anywhere, creating effects like soft clouds or glows, because you're filling in pixels (or dots).
Here is a quick example I created using Procreate:
If you were to zoom in on this image, say the driver's eye, you'd see pixelation:
But what if you wanted to enlarge this image as big as a wall and it not lose any quality? Ahhh, there, you'd need a vector file.
Vector:
Vector files are made out of lines. (To have a line, you need two or more points). But as you move closer, the points that form the lines maintain uniformity, so there is no degradation of quality, no pixelation. Put simply: Vector files are held together by Math.
Here is that image again converted into a vector file:
You notice there is a more of a clear separation of color because each color is a line.
But if we zoom into the eye again, you'll notice the lines remain sharp:
This is why almost all logos are made with vectors. You can make them as large as field or as small as a keychain and use the same source file for all.