A more thorough explanation:

Definition: Quit means to stop doing something. It can also mean to leave or vacate real property. For example, a landlord may give their tenant notice to quit the premises.

A notice to quit is a written notice sent by a landlord to a tenant stating that the landlord wishes to reclaim the property and that the tenant must vacate the premises by a particular date. This notice is usually physically served on the tenant or placed in a visible location such as the front door, with a copy provided by certified mail. If the tenant fails to vacate the premises after receiving the notice, the landlord may file a lawsuit for unlawful detainer (often referred to as eviction).

Another example of quitting is when a participant terminates their employment for any reason other than death, disability, or retirement.

Example: Sarah decided to quit her job at the restaurant because she wanted to focus on her studies.

This example illustrates the definition of quitting as stopping doing something, in this case, Sarah stopping her employment at the restaurant.

Example: The landlord gave the tenant a notice to quit the premises because they were behind on rent.

This example illustrates the definition of quitting as leaving or vacating real property, in this case, the tenant being required to leave the premises due to not paying rent.

See also: 30-day notice, cure or quit