Retirement tax questions

Ok so the IRS will know the total amount of contributions that I made to the Roth IRA since it first started? Because that is what determines if it is taxable or not.

 

Also, I found the information below here: https://www.irs.gov/help/ita/is-the-distribution-from-my-roth-account-taxable

 

For a Roth IRA distribution:

 

- Whether or not you have a cost basis to recover. Your basis is the amount of contributions in your Roth IRAs.
- The year a Roth IRA was first established for your benefit.