In LDS (Mormon) theology, what is the Aaronic Priesthood and to whom is it conferred?

I understand that the LDS church institutes that Aaronic Priesthood. In the Old Testament, this was specifically reserved to the tribe of Levi and the family of Aaron. > and you shall gird **Aaron and his sons** with sashes and bind caps on > them. And the **priesthood shall be theirs by a statute forever**. Thus > you shall ordain Aaron and his sons. Exodus 29:9 ESV In the LDS Church, is this the same priesthood? If so, what is the doctrinal precedent where people other than Jews from the tribe of Levi and the family of Aaron can be given that priesthood? Who receives that Aaronic priesthood today and how long is it held?