Vectors act like images, but render differently and aren’t rastered. Images are rastered, meaning that their quality can be heavily degraded if scaled up. Vectors are scalable at all times without losing quality, and are rendered instead by a rendering engine that supports scalable vector graphics (.svg files).
Vectors are especially important for icons and stuff. Inkscape is the absolute best freeware vector design program, and many have used it for icons, projects, and business, and more.
Another cool thing about vectors is that you can easily export them as .PNG files (if you have Inkscape or any other image editor different from MS Paint), and even at higher scales, by just resizing vectors!
This is a vector icon that I have been using to create one of my Roblox plugins at the moment, and it’s going to turn out nicely (hopefully).
To prove my point of them not losing quality, go right-click the image above, maybe open it in a new tab. Zoom in to maybe 500%, and you can see the difference already! It has not lost quality, even when upscaled so high!
Also the system used for SVG files, they are created out of paths, lines, strokes, fill colors, stroke weights, stroke styles, and more.