Glossary of terms
Here you'll find quick explanations of the most common quantum computing terms. Stumbled across a word that made zero sense? Chances are, it's covered right here.
Think of these definitions as your cheat sheet - enough to get your intuition up to speed so the technical stuff stops feeling like a wall and you can actually focus on the big picture.
Qubit:
A quantum bit, the fundamental unit of information in a quantum computer. Unlike a classical bit, which can be either 0 or 1, a qubit can exist in a superposition of both states — meaning it simultaneously represents 0 and 1 with certain probabilities.
Superposition:
A quantum phenomenon where a qubit can exist in a combination of multiple possible states at once. Only when measured does the qubit “collapse” into a specific outcome. This property is essential for the parallel processing capabilities of quantum computing.
Entanglement:
A special quantum correlation between qubits, where the state of one instantly determines the state of another, regardless of the distance between them. Entangled qubits are not independent — their states are linked in a way that cannot be explained by classical physics. This effect underpins many quantum algorithms and communication protocols.
Decoherence:
The process by which a quantum system loses its quantum properties, such as superposition and entanglement, due to interactions with its environment. In practical terms, quantum information “leaks” into the surroundings and becomes effectively classical. Decoherence is one of the main challenges in building stable quantum computers.
Interference:
A phenomenon where the probability amplitudes of quantum states combine — either reinforcing or canceling each other out. This allows desired outcomes to be enhanced and unwanted ones suppressed. It is a key feature exploited in many quantum algorithms.
