In physics, a **quantum** (plural quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. ... Quantization of energy and its influence on how energy and matter interact (**quantum** electrodynamics) is part of the fundamental framework for understanding and describing nature.

**Quantum is the** Latin **word** for amount and, in modern understanding, **means** the smallest possible discrete unit of any physical property, such as energy or matter. **Quantum** came into the latter usage in 1900, when the physicist Max Planck used it in a presentation to the German Physical Society.

**Quantum** mechanics is a fundamental **theory** in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all **quantum** physics including **quantum** chemistry, **quantum** field **theory**, **quantum** technology, and **quantum** information science.

Quantum computing is the exploitation of collective properties of quantum states, such as superposition and entanglement, to perform computation. The devices that perform quantum computations are known as quantum computers.

**Quantum computers** perform calculations based on the probability of an object's state before it is measured - instead of just 1s or 0s - which means **they** have the potential to process exponentially more data compared to classical **computers**. ... A single state - such as on or off, up or down, 1 or 0 - is called a bit.

A **quantum computer** encodes information into **quantum** states and computes by performing **quantum** operations on it. There are several tasks for which a **quantum computer** will be useful. ... Or we **could** model chemical reactions—because interactions among atoms in a chemical reaction is a **quantum** process.