Yep, it's all the same, no distinctions or tracking of gains.
Except......non-deductible IRA contributions. Then it can get hairy. Since you never deducted it when you put it in it sort of acts like a Roth. The principal you put in is not taxable upon withdrawal. I'm not certain what happens with the gains, but I'm fairly sure they're taxed. Hopefully the brokerage house holding the funds is tracking that crap, but I'm not sure who he burden is on.
Roth, not taxed at all.
Traditional withdrawals (or conversions to Roth) go on line 15 on page 1 of the 1040, they increase your AGI, they are not subject to FICA (since you paid that upon earning the income), any normal deductions/exemptions can reduce them before arriving at taxable income, and any credits you have can be used to offset the tax.