Leads are not converting to Accounts

Leads are not converting into accounts when I try. Instead, they only create contacts &, if I choose, potentials. There is nothing to click or even read that indicates that creating an account with the lead information is an option.

Am I wrong in thinking that converting a lead creates both an account & a contact, with the option of creating a potential as well?

What can I do to make it so that all that information from the lead becomes an account? The information won't transfer from a closed won potential into an account either.