A raster image is made of up pixels, each a different color, arranged to display an image. A vector image is made up of paths, each with a mathematical formula that tells the path how it is shaped and what color it is bordered with or filled by.
The major difference is that raster image pixels do not retain their appearance as size increases – when you blow a photograph up, it becomes blurry for this reason. Vector images do retain appearance regardless of size, since the mathematical formulas dictate how the image is rendered. (https://www.psprint.com/resources/difference-between-raster-vector/)
Raster images are capable of displaying a myriad of colors in a single image and allow for color editing beyond that of a vector image. They can display finer nuances in light and shading at the right resolution. Vector images are scalable, so that the same image can be designed once and resized infinitely for any size application from business cards to billboard.
Raster images cannot be made larger without sacrificing quality. Vector images cannot display the natural qualities of photographs. Raster images are often large files, while vector images are relatively lightweight. Raster images are used in web and print, vector images cannot as of this writing be used in electronic format – they must be converted to a raster first. Vectors display at the highest resolution allowed by the output device, while rasters blur when blown up.(https://www.psprint.com/resources/difference-between-raster-vector/)
In photoshop raster images are described by an array or map of bits within a rectangular grid of pixels or dots. Vector images are described by lines, shapes, and other graphic image components stored in a format that incorporates geometric formulas for rendering the image elements.(https://helpx.adobe.com/photoshop/key-concepts/raster-vector.html)a raster graphic (also sometimes called a bitmap graphic, but not to be confused with the .bmp file format) is an image that’s comprised of tiny blocks of colour called pixels. Zoom in close enough on a raster image, and it begins to pixelate, like a mosaic. (http://www.macprovideo.com/hub/photoshop/photoshop-vs-illustrator)
The vector image is created by defining points and curves. This vector image was created using Adobe Illustrator. When vector graphics are scaled, the edges remain crisp and sharp no matter the size.(https://helpx.adobe.com/photoshop/key-concepts/raster-vector.html)
Examples of raster-based images include photographs, scans, digital paintings, website components like buttons and header graphics, and any other image that’s made up of a lot (like, millions) of colours. Raster-based file formats include JPEG, GIF, PSD, PNG, and a few others.(http://www.macprovideo.com/hub/photoshop/photoshop-vs-illustrator)