Classical computing is built on bits — each bit is either 0 or 1. Every computation, every app, every website is ultimately combinations of zeros and ones processed very, very fast.
Quantum computing changes the fundamental unit. A qubit can be 0, 1, or — here’s the weird part — both at the same time (superposition). And qubits can be entangled with each other, meaning the state of one instantly affects the state of another regardless of distance.
Why this matters: certain problems that are practically impossible for classical computers become tractable for quantum computers. Not all problems — specific types:
- Cryptography — quantum computers could break most current encryption. This is both a threat and a motivation for developing quantum-resistant cryptography.
- Drug discovery — simulating molecular interactions at the quantum level. Classical computers can’t do this efficiently for complex molecules. Quantum computers can.
- Optimization — finding the best solution among billions of possibilities. Logistics, financial modeling, materials science.
- Machine learning — potentially accelerating certain types of ML training and inference.
The current state (as of 2025):
- Quantum computers exist but are noisy, error-prone, and limited in scale
- We’re in the “NISQ era” (Noisy Intermediate-Scale Quantum)
- Practical quantum advantage over classical computers has been demonstrated for narrow tasks
- General-purpose quantum computing is still years away
- Major players: IBM, Google, Microsoft, Amazon, and various startups
For entrepreneurs and technologists: you don’t need to understand the physics deeply. You need to understand which problems quantum computing will eventually solve better than classical computing, and which industries will be disrupted when that happens.
Related: Automation & Artificial Intelligence (AI), Future tech