What is the main way a representative democracy differs from a direct democracy?

Citizens elect leaders who vote on the issues in a representative democracy, and citizens vote on the issues in a direct democracy.
A representative democracy is modern, and a direct democracy is ancient.
A representative democracy works better in small groups, and a direct democracy works better in large groups.
Citizens’ desires are ignored in a representative democracy, and citizens’ desires have a better chance of being heard in a direct democracy.