Yes, you can maintain both types of IRAs at the same time. You can even make contributions to both types of IRAs in the same year. But your contributions to both Roth and traditional IRAs cannot exceed the maximum contribution limit for all IRAs.
There are limits on the amount of income one can make during a given year—and the limits change from year to year. Please visit the IRS website for details.
A Roth IRA is an individual retirement account created by the Taxpayer Relief Act of 1997. Roth IRA accounts are traditionally used as retirement savings accounts. They allow limited contributions to be made throughout the tax year and can be withdrawn within 5 years after establishing the account provided you are aged 59 1/2 or older.