Seniority refers to the length of time that an individual has been a member of a particular organization or group, typically in the context of employment. In most organizations, seniority is used as a basis for determining various benefits, privileges, and rights, such as pay increases, promotions, vacation time, and job security.

Seniority can be measured in different ways, such as the number of years an individual has worked for an organization or the length of time they have held a particular position. In some cases, seniority may also be based on factors such as performance, experience, or education.

Seniority is often seen as a way to reward loyalty and dedication to an organization, and it can help to create a sense of stability and continuity within a workplace. However, it can also be a source of tension and conflict, particularly when it comes to issues such as layoffs or promotions, where decisions may be based on seniority rather than merit or performance.