This would be the definition of an obligation.
It has congress & the senate in it together to pass laws. Like, a bill comes from congress and congess then passes it on to the senate. The senate could deny the bill if the less majority rules in the senete, it is gone if more than it goes on to the president which is the exective branch he can veto (reject) the bill or it could turn into a law. I hope this helps XD.
Modern era was is the term that historians use to describe the historical period between the beginning of the 16th century and the 21st century.
