Q.What Are Political Earmarks?

The Congressional Research Service, the public policy research arm of the U.S. Congress, defines them as:
“Provisions associated with legislation(appropriations or general legislation) that specify certain congressional spending priorities or in revenue bills that apply to a very limited number of individuals or entities. Earmarks may appear in either the legislative text or report language(committee reports accompanying reported bills and joint explanatory statement accompanying a conference report).”

For example, say you have a bill that would develop high speed rail around the country for 1 billion(round number) to be administered by the department of transportation. The usual allocation of the funds would go through an application process administered by the executive branch. But say a senator puts an earmark in that 1 billion, that 100 million of it is for their state or awarded to a specific person/persons in particular. That means if the bill passes, 1/10th of that budget will go to that state or person/persons and only the remainder will be subject to the usual process. That’s an earmark.