We just had a snowstorm. You wake up early to check Twitter and read that classes are cancelled.
You tell your friends and you all go out to enjoy the snow. Unfortunately, only morning classes were cancelled and one of your friends was marked absent from their afternoon class. You didn't mean to give your friend bad information, you just misread the announcement. You have given your friend misinformation.
Same scenario - only this time you don't actually like that "friend." You tell them classes are cancelled, knowing they have an afternoon class and that they will miss it. You intentionally deceive that person so that they will miss their class. You have given them disinformation.
The difference is in the intent.