FAQ: What's the difference between an account and a name?
Accounts remember a balance, where Names don't. Names are only there so that you don't need to keep entering them.
For example, you'd want to see a balance for your Checking account or Visa card, so you should set them up as Accounts. But Amazon or iTunes, where you might frequently charge items but don't need a running balance, would probably be Names.
Note: A name should refer to a single entity. "Wal-Mart" would be a good name, but "Groceries" would not. "Groceries" would be better used as a category, since it can refer to multiple different items and you would want to be able to total something by category, i.e to see all of your grocery or pet spending.