While you can begin making qualified withdrawals from a traditional IRA at age 59 ½, you must start taking withdrawals that are known as "required minimum distributions" starting in the year you turn 70 ½. The amount of the distribution depends on how much you have saved in the account and your life expectancy, according to tables published by the IRS.
If you don't make the distributions, or don't take out enough, you could be subject to a 50% tax on the amount you would've been required to take out.
SEP and SIMPLE IRAs also come with required minimum distributions.
If you have a Roth IRA, you aren't required to take distributions and you can leave the money in for as long as you want. When you do make withdrawals you can do so in whatever amounts you like since you will owe no tax on that money.