A handle is a part of, or attachment to, an object that allows it to be grasped and manipulated by hand. The design of each type of handle involves substantial ergonomic issues, even where these are dealt with intuitively or by following tradition. Handles for tools are an important part of their function, enabling the user to exploit the tools to maximum effect. Package handles allow for convenient carrying of packages.The three nearly universal requirements of are:

Sufficient strength to support the object, or to otherwise transmit the force involved in the task the handle serves.Sufficient length to permit the hand or hands gripping it to reliably exert that force.Sufficiently small circumference to permit the hand or hands to surround it far enough to grip it as solidly as needed to exert that force