I was reading through this and hope you've gotten out of it what you need to know. But to summarize and add my thoughts:
An individual can only put away $5500 a year into an IRA, whether a traditional or Roth. Under ceratin income levels, you can choose to do either
- you have chosen to contribute to the traditional IRA, which in your tax bracket means that you can deduct the $5500. Just know that in the future, you withdrawals will be taxed at your then current tax rate...
- you could also choose to contribute to a Roth IRA instead. If you do this, you still pay taxes on that $5500, but it will never be taxed again.
So if you are really in the 12% bracket now and are young and you are managing to save extra, you might want to just contribute to the Roth IRA instead. You pay some money now, but you could save a lot of money on taxes in the future.
As far as the backdoor Roth IRA - these are used for people with high incomes, around $200k for a married couple this year. The reason for this is that at that income level, a person cannot contribute directly to a Roth IRA (make too much money). They can contribute to a traditional IRA, but cannot take the tax deduction (again, make too much money). But due to a strange loophole, you can contribute your non-deductible money to a traditional IRA, wait until the money clears, and then transfer it to a Roth IRA, and that is allowed. It can be more complicated than that, but that is the general gist of the "backdoor IRA".