OCD stands for Obsessive Compulsive Disorder. People with OCD have uncontrollable thoughts that are "obsessions." There are actions people with OCD feel the need to repeat over and over.
Fear of germs
Wanting or needing things in order (by color, size, etc)
Thoughts about harming yourself or others
Unwanted Thoughts
Sanitizing hands
Checking if stuff are turned off, locked, etc.
Wanting reassurance
Saying words over and over in your mind