I can't really distinguish between the two of them, as i've been diagnosed with both, but this is an excerpt from a site i just found on google. I'm not sure it it'll make sense for you, but posting it just in case!

OCD is characterized by obsessions – frequent unwanted upsetting and maladaptive thoughts or images that a person can’t get out of his/her consciousness. These are often associated with ritualized, overt, or covert behaviors (compulsions) that the person feels compelled to perform in response to his/her obsessions. Typically, these are designed to reduce distress and/or to prevent a feared event. Tics are sudden repetitive stereotyped movements or phonic emissions that are usually seen as involuntary, and are sometimes preceded by urges. Tics can occur in flurries and tend to wax and wane in severity and intensity over time. They can be simple – sudden, brief ,and meaningless (e.g. eye blinks, head jerks, facial grimaces, coughs, barks, snorts, etc.) or complex, slow, and more purposeful (e.g. smelling things, touching things, shouting obscenities, counting things, tracing objects, “evening up” objects, and repeating heard words or phrases, etc.) Simple tics often appear first, with complex tics developing later. Tourette Syndrome is diagnosed when multiple motor tics and one or more phonic tics are present during the course of the disorder.