Real estate agent
The seller signs a listing agreement specifing the commission to be paid, the term of the listing, and other details of the arrangement. The realtor representing the buyer is also paid a commission as specified in the listing agreement.
The listing agent works with the seller to get the property ready to sell and to market the home with a listing in Realtor.com, advertizing, open house, and similar techniques.
When an offer is received, the realtors work with their clients to try to reach an agreement. Once a completed contract is signed, the agents then work to keep the deal together though necessary inspections, appraisal, adjustments, and approvals.
Finally at the close, the buyer brings a check, and both realtors and the seller get paid.