There’s often some confusion about the difference between vector and raster images, especially when trying to source quality logo files. The purpose of this guide is to simply explain the difference between these two image types and where you might find them.
Raster images are probably how you’d expect an image to be saved on a computer. The file is made up of tiny ‘dots’ called pixels. In the above image you can see that when the raster image is increased in size, it becomes pixelated. This is because the same amount of pixels have been made larger to increase the size in the image.
Photographs are saved in a raster file size because it can capture more fine details and colours when in high resolution. A high resolution raster image will have more pixels and a larger file size.
Photographs will usually be saved in the ‘.jpeg’ format and graphics will usually be saved in ‘.gif’ or ‘.png’ format.
Vector images work very differently to raster images. Vector images are drawn by computer software from information about geometrical shapes and lines. Because of this, the graphic can be resized without sacrificing quality. The above image shows what a vector graphic would look like when made much larger, compared to a raster one.
Because vector images are made up of shapes and lines, it is very difficult to have fine details that would be found in a photograph, so it is not used for photography. The vector format is particularly useful for logos and other graphics that may need to be scaled and manipulated. A logo that is saved in vector can be easily scaled without losing quality to suit a wide range of purposes from websites to billboards.
Vector images are typically saved in ‘.svg’, ‘.eps’ or ‘.pdf’ format.