In everyday life we use computers that rely on bits — tiny units of information that can be either 0 or 1. These are the “classical computers” that power laptops, phones and supercomputers.
But in the realm of quantum computing, we use qubits — quantum bits — which can behave in ways bits simply cannot. According to National Institute of Standards and Technology (NIST), qubits leverage the laws of quantum mechanics, allowing new types of computation.

How classical and quantum computers compare

• Classical bit (0 or 1): A classical computer processes data by switching bits on/off or 0/1 in sequence.
• Quantum qubit (0, 1 or both): A qubit can exist in a superposition of both 0 and 1 at once — imagine flipping a coin and it’s both heads and tails until it lands.
• Entanglement: Qubits can become entangled so that the state of one qubit instantly influences another, even if they are far apart. This is one of the quantum features that gives quantum computers potential power beyond classical machines.
• Parallelism: Because of superposition and entanglement, quantum computers can explore many possible solutions simultaneously rather than sequentially. That means for certain problems they can be far faster than classical machines.

What makes quantum computing a big step forward

1. New types of problems become solvable: Some problems are so complex that even supercomputers would take decades or centuries. Quantum computers have the potential to tackle those in much shorter time spans.
2. Different computing paradigm: Rather than simply faster versions of current computers, quantum machines use a fundamentally different approach to computation — tapping into quantum physics rather than just switching circuits.
3. Industry-changing potential: According to a June 2025 report by McKinsey & Company, quantum technology could reach global revenue of up to $97 billion by 2035, with quantum computing forming the largest share.
4. Complement rather than replace: Classical and quantum computers are expected to work together. Many tasks will remain in the domain of classical computers, while quantum machines will handle the truly hard problems.

Interesting examples in plain terms

• Maze solver analogy: A classical computer walking through a maze might try one path after another. A quantum computer can explore many paths at once — giving it a big advantage for maze-type, branching problems.
• Drug discovery: Suppose a scientist is searching for a new molecule that can bind to a virus protein. A quantum computer could simulate many possible molecular configurations simultaneously, reducing the time and cost compared to classical simulation.
• Optimization for logistics: Imagine a delivery company with thousands of routes and dozens of constraints (traffic, fuel, time windows). A quantum machine might find an optimized plan much faster than classical methods because it can evaluate many combinations in parallel.

What quantum computers cannot (yet) do

• They are not ready to replace your laptop or smartphone. Current quantum machines are noisy, small-scale and specialised.
• They are only dramatically faster for certain specific problems, not all computing tasks. For everyday tasks like web browsing, word processing or streaming video, classical machines remain best.
• They face major technical challenges: qubits are fragile; error correction is difficult; scaling up to large numbers of qubits is very hard.

Why it matters to you, even now

Even though quantum computers are still emerging, their impact is likely to reach everyday life sooner than many expect:

• Security: Many current encryption systems could be vulnerable in a future world with powerful quantum computers — prompting work on “quantum-safe” cryptography.
• Medicine & materials: Faster simulation of molecules and materials may lead to new drugs, better batteries, cleaner energy and stronger materials.
• Business & logistics: Industries such as finance, logistics, energy and manufacturing are investing in quantum to gain a competitive edge.
• Technology readiness: With 2025 declared by the International Year of Quantum Science and Technology (IYQ) by the United Nations, more public awareness, investment and research are happening now.

The journey ahead

The quantum computing world is currently in the NISQ (Noisy Intermediate-Scale Quantum) era — machines with tens to a few hundred qubits that aren’t yet fault-tolerant. The next big step is building large-scale, error-corrected quantum computers, which may come in the late 2020s or early 2030s.

Until then, we will see hybrid quantum-classical systems, application-specific quantum machines, and growing quantum ecosystems. As research, hardware and software advance, quantum computing will increasingly make its way from “interesting experiment” to “practical tool.”

In summary

Quantum computing changes the game by allowing certain problems to be solved in ways classical computers cannot. While still in early stages, the technology is already shifting how we think about computation, science, technology and industry. In 2025, quantum computing is no longer just a distant dream — it’s preparing to transform the future.