Traditional (Hawley) retainers have a piece of wire attached to plastic (or acrylic). Clear retainers (Essix) are also plastic but don't have any wires. Both are custom-made to fit your teeth.
This is a legal contract between the law firm and the client setting forth the terms of the legal services to be provided and how the client will be charged for the services.
A retainer agreement is a work-for-hire contract. It falls between a one-off contract and permanent employment, which may be full-time or part-time. Its distinguishing feature is that the client or customer pays in advance for professional work to be specified later.
A retainer agreement, for example, means that agencies receive ongoing payment from their clients. A one-off contract, on the other hand, revolves around a particular service that an agency provides its client for a specified time.
A retainer-based structure is one in which the client pays a fixed amount—generally monthly or quarterly—for ongoing work. But unlike project-based or hourly-based work, marketing agency retainers are far more predictable for both the agency and the client.
Retainership is formed within English, by derivation. Etymons: retainer n. 2, ‑ship suffix.
Retainer agreements (also referred to as representation agreements) are a type of compensation agreement with lawyers either for reserving their employment or as compensation for future services. Also inside the agreement are details on the scope and procedure for the representation.