A more thorough explanation:

Sergeantry, also spelled sergeanty, refers to a feudal lay tenure that required some form of personal service to the king. This service was not necessarily military and could be as small as presenting an arrow or an unstrung bow to the king. There were two types of serjeanty:

Grand serjeanty was a serjeanty that required the tenant to perform a service relating to the country's defense. The required service could be as great as fielding an army or as small as providing a fully equipped knight. Sometimes the service was ceremonial or honorary, such as carrying the king's banner or serving as an officer at the coronation.

Petit serjeanty was a serjeanty that required only a minor service of small value, usually with military symbolism. An example of petit serjeanty is presenting an arrow or an unstrung bow to the king.

Many household officers of the Crown, even those as humble as bakers and cooks, held lands in serjeanty. This illustrates that the required service was not necessarily military and could be any form of personal service to the king.