"Roth" and "Traditional" are two kinds of tax treatment for accounts. Roth you pay tax now, but it is tax free coming out, and traditional is tax free now, but you pay tax coming out. Your 401K has a combined limit of 19K of employee contributions, so for example if you contribute 10K to traditional, you can only contribute another 9k to either traditional or Roth.
IRA accounts, be they traditional or Roth, are on a different contribution limit from your 401k. In your IRAs you have a limit of 6k of contributions. Same as your 401k, this is the combined limit of both traditional IRA or Roth IRA.