It is a difficulty in learning and remembering the muscle movements used to write. Students have trouble putting their thoughts on paper, because they have to focus on forming the letters.
Signs may include cramped fingers after a short time writing, lots of erasing, mixing print and cursive letters, or watching the hand while writing.
Dysgraphia, like all learning differences, doesn't mean a kid is dumb or lazy. Special help with assignments, extra practice, or special classes in school can all help.