What is a form 1040 for?

Yes, a 1040 is used by sole proprietors with a Schedule C attached to it along with other individuals who have more than a simple return.  If you are filing as a self-employed business owner, you will need to use TurboTax Self-Employed to complete this return.

A 1040 return is a personal individual return that can include schedule C for sole proprietors/independent contractors/freelance/sub-contractor/outside Consultant, etc.  They are all self employment income.

But if you need to file a separate business return like a 1065 Partnership or multi-member LLC or a 1120 S Single Member LLC or C corp you need Turbo Tax Business.