How do employees save on taxes with an HSA?

How do employees save on taxes with an HSA?

Account holders receive a "triple tax benefit":

Reduce taxable income - HSA contributions through payroll are made pre-tax, which lowers tax liability on paychecks. Manual contributions are tax deductible when filing taxes each year.
Tax-free earnings - Interest growth earned on HSA funds is never taxed.
Tax-free distributions - HSA funds are not taxed when used for eligible expenses.