There is no Schedule ES. I assume you mean Form 1040-ES.
Schedule SE is the form that is used to calculate the self-employment tax on your federal income tax return if you have self-employment income. It's part of the tax return that you file at the end of the year. The self-employment tax on Schedule SE is included in the total tax on your tax return.
Form 1040-ES is the form that's used to make quarterly payments of estimated tax.
