A drop shipper is the person who 'holds' all the products you are selling and after you sell it, you buy it from the 'dropshipper' who then mails it to the customer for you.
You are now the middle man, and in a way, you'll be splitting the profit with the dropshipper. Dropshiping is OK if you don't have a lot of money to start with IMO, but after some profits start rolling in, I would suggest you start having your own inventory. This way you don't have to share the profit.
Good luck and happy selling!