"The Congressional Research Service (CRS) serves as shared staff to congressional committees and Members of Congress. CRS experts assist at every stage of the legislative process -- from the early considerations that precede bill drafting, through committee hearings and floor debate, to the oversight of enacted laws and various agency activities.
CRS approaches complex topics from a variety of perspectives and examines all sides of an issue. Staff members analyze current policies and present the impact of proposed policy alternatives." -- https://www.loc.gov/crsinfo/about/