A Retainer Contract is a type of agreement between a client and a service provider, where the client pays an agreed-upon fee for a certain amount of work to be completed each month. This type of contractual arrangement allows businesses to secure the services of experienced professionals on an ongoing basis, and gives them greater assurance that their needs will be met efficiently and professionally. It also provides flexibility to companies, as they can hire the right specialists for specific projects without having to take on long-term employees.