Al retirement accounts are like individual investors, depending on their type they have restriction on how you can move money around in them. But within those rules you can do what you want.

Likewise each has its rules as to what happens if you take money out and when you can take money out.

The easiest way for you to look at any investment is if you consider it is separate from you, basically a totally independent entity. You are then going to look at what it will do over time (growth analysis), what it gives you or cost you to do business with it (the benefits and costs of moving money in and out by various ways).

If you can not understand it from reading their literate, and rarely can anyone (financial services industry uses more double talk then anyone else), then talk to a financial adviser. If you do not understand him, then spend a few dollars and talk to an accountant (not a bookkeeper or banker), if they or you still do not understand something after the conversation, then avoid the investment. If you do not understand what you are investing in, then it is a dangerous and dumb investment for you to make regardless of what it is.