Bitmap images are made up of a group of small, tiny square dots called pixels. Each pixel is given a colour and arranged in a pattern to form an image. When you zoom into a bitmap image you can see the individual square pixels that are arranged to create an image. Bitmap graphics can be edited by removing or changing the colours of individual pixels using programs such as Adobe Photoshop.
Vector images do not use these pixel patterns. They instead use mathematical formulas to draw lines and curves that can be used to create an image from geometric shapes such as circles and polygons. These images are edited by manipulating the lines and curves that make up the vector image using programs such as Adobe Illustrator.
So why are vector images important?
Vector images have a lot of advantages over bitmap images. Due to the mathematical formulas that are used to create the vector image, it means that the file is smaller as it only has to store this information, whereas bitmap images have to store the colour information and pixel pattern for the image.
The main advantage however is that a bitmap image can only be scaled in size a certain amount before the image becomes deformed, jagged and “pixelated”. Meaning that you start to see the squares that make up the pixel pattern, which is not a clean or attractive look. However vectors can be stretched and scaled to any size and will always retain its shape, due to the mathematical geometry that makes up its shape. It will always look clean, and smooth even if you stretched the image a mile long.
Vector images tend to be made up of limited block colour images and for this reason are useful in logo design. Whereas bitmaps are much more complicated and can be photographs made up of thousands of colours.