Raster images consist of pixels while vector images consist of paths and curves. Let us elaborate what it means.
Vector images are formed by combination of lines and curves, each of which are given a colour value. These lines and curves have certain node positions which allow us to represent different shapes (formed from these lines and curves) in a mathematical equation.
Do you remember ?A vector has a given direction and magnitude(or length). Well this is a reminder for those who have studied mathematics or physics.
How does this designing approach help ? Well with this, you can resize your image the way you want, and you won’t loose out file resolution. It means your image will not look pixelated or cloudy when you zoom in. For example, when we zoom in a font, it looks fine and doesn’t seem to be pixelated.
Vector images are mainly used for creating Logos. Even they are used in printing T-Shirts, posters, brochures and creating business cards. Also vector images have smaller size and weight as compared to raster images.
Raster Image is an array of pixels and each pixel is assigned a colour value. They are often called bitmap images, because information contained in them is directly mapped in display grid. Raster images are resolution dependent which means on zooming in or out, there is loss of clarity and result in cloudy or blurry image. Also they contain more information than vector images. Also, higher DPI (Dots Per Inch) and PPI(Pixels Per Inch) in raster images results in larger image size and weight.
Raster images are used in Web Design and editing photographs.
If we talk about best software used in raster and vector image editing, Adobe Illustrator is best for designing logos i.e. Vector Graphics. On the other hand Photoshop leads in Raster Graphics editing. You can also try some free Open Source Software.