Traditional IRA
You can start taking penalty free distributions once you reach the age 59 1/2.
There are required distributions starting at age 72. Withdrawals from traditional IRA's are taxable income.
Roth IRA
You can start taking penalty free distributions once you reach the age 59 1/2 and the funds have been invested for 5 years.
There are no mandatory distributions for a Roth IRA.