Raster editing uses a lattice-like grid. Each grid unit contains a pixel. A pixel is a picture element, or dot, on the screen. Together these pixels form a character. By turning these pixels on and off and setting the pixels to different sizes, you can create a new character or slightly alter an existing character.
Vector editing uses a coordinate grid.
You can set points in this grid, and connect the points to form lines. To create a curve in a character, you connect a series of short, straight lines. Together, all these lines form a character. Raster editing is faster but is somewhat limited in what it can do. Scaling and other geometric transformations cannot be easily performed in raster editing.