Gd is a graphics library for drawing .gif files. Gd allows your code to
quickly draw images (lines, arcs, text, multiple colors, cutting and
pasting from other images, flood fills) and write out the result as a
.gif file. Gd is particularly useful in web applications, where .gifs
are commonly used as inline images. Note, however, that gd is not a
paint program.
Install gd if you are developing applications which need to draw .gif
files. If you install gd, you'll also need to install the gd-devel
package.