A gadget is a device or an appliance that has a useful specific practical purpose and function but is often thought of as a novelty. Gadgets are invariably considered to be more unusually or cleverly designed than normal technology at the time of their invention. Gadgets are sometimes also referred to as gizmos. In some circles the distinction between a gadget and a gizmo is that a gizmo has moving parts, whereas a gadget need not have them.citation needed For example, a digital watch would be a gadget, while an analog watch would be a gizmo. Thus a gizmo is essentially a mechanical gadget.

Multiple types of gadget.
* Mechanical gadgets
Clocks, bicycles, and thermometers are amongst the very large number of gadgets that are mechanical and also very popular. The invention of mechanical gadgets though is based more on innovation of the inventor rather than education.[citation needed]

*Electronic gadgets
Electronic gadgets are based on transistors and integrated circuits. Unlike the mechanical gadgets one needs a source of electric power to use it. The most common electronic gadgets include transistor radio, television, cell phones and the quartz watch.

* Programmable gadgets
Most of the modern gadgets belong to this category. These gadgets are invariably based on a microprocessor and often have flash memory.[citation needed] They use embedded software which controls their functions. Such gadgets are found not only in the pockets of gadget freaks, but also in their cars and homes. Some examples of gadgets in this category are notebook computer, mobile phone, iPhone etc.

* Application gadgets
Computer programs that provide services without needing an independent applications be launched for each one, instead run in an environment that manage multiple gadgets. Their are several implementations based on existing software development techniques; like JavaScript, form input, and various image formats.