A raster graphic is made up of a collection of tiny, uniformly sized pixels, which are arranged in a two-dimensional grid made up of columns and rows. Each pixel contains one or more bits of information, depending on the degree of detail in the image.
Answer:a collection of tiny, uniformly sized pixels, which are arranged in a two-dimensional grid made up of columns and rows. Each pixel contains one or more bits of information, depending on the degree of detail in the image.
The difference is when you draw by memory you won't remember every tiny detail, and you make/draw it in your own way vs. having the object in front of you you can copy it almost exactly.