If you're applying for a federal grant, you may come across a requirement to share in the cost of your project. This is called matching or cost sharing. In short, it means that part of the total cost needs to be covered by non-federal sources.
Matching amounts are usually shown as a percentage of the total project cost. These percentages, along with rules about which funds can be used, vary depending on the program. Always review the Notice of Funding Opportunity (NOFO) or other official guidance for your specific grant.