Conventional computers store information in bits. Quantum computers use qubits: physical systems that can be prepared, manipulated and measured according to quantum mechanics. Quantum gates change their state, while a designed algorithm uses interference and entanglement to make useful measurement outcomes more likely.
Quantum computers exist, but building large, reliable systems for a broad range of useful problems remains a research and engineering challenge. Noise damages calculations, and error correction requires additional resources. Qubit count alone cannot compare machines: operation quality, connectivity and useful computation time also matter.
Potential applications include molecular and materials research and particular mathematical problems. A quantum computer is not automatically faster at every task. Saying it tries everything simultaneously misses the challenge of extracting a useful answer. For Alien News readers, this distinction helps interpret computing claims. Quantum hardware does not itself establish quantum explanations for consciousness or unusual phenomena; those proposals need their own mechanisms and evidence.