Modding is the act of modifying hardware, software, or anything else to perform a function not originally intended by the designer, or to achieve bespoke specification or appearance. The term is often used in reference to video game modding, particularly in regard to creating new or altered content and sharing that via the web. It may be applied to the overclocking of computers in order to increase the frequency at which the CPU operates. Case modding is a popular activity amongst many computer enthusiasts which involves the customization of a computer case or the installation of water cooling technology. In connection with automobiles, modding can connote engine tuning, remapping of a vehicle's engine control unit or customization of the coachwork.

The word bespoke has evolved from a verb meaning 'to speak for something', to its contemporary usage as an adjective. Originally, the adjective bespoke described tailor-made suits and shoes. Later, it described anything commissioned to a particular specification. In contemporary usage, bespoke has become a general marketing and branding concept implying exclusivity and limited runs.