Shaving your head to make it thicker question?

Okay, well I heard that shaving your head can make it grow in thicker, but i also heard it could make it sparse. Also, can you give me a definition of sparse? I think it means no density, but I really don't know. Anyways, before I make this decision, is it a good choice or a bad choice? It's to make my hair thicker, or will it do the opposite? Thanks.