What Is Quantum Computing Here S Everything You Need To Know Fast

Bonisiwe Shabane

-Jan 2, 2026, 5:20 PM

what is quantum computing here s everything you need to know fast

Our editors will review what you’ve submitted and determine whether to revise the article. Quantum computers work by exploiting the dual nature of matter: since matter, according to quantum mechanics, can behave as a wave or as regular particles, it can exhibit wave properties. Qubitsare the quantum equivalent of classical bits (the smallest unit of data used in computer operations) and the fundamental units in quantum data storage that display wave nature. While classical bits can either hold the value 0 or 1, qubits can hold multiple possible values at once through a property called superposition. In quantum mechanics superposition is a property through which particles at the atomic scale can occupy multiple possible energy states simultaneously. When an observation, or measurement, is made, the particles “collapse” into a single definite state.

Qubits can exist in a superposition of states and hold the value 0, 1, or both simultaneously. The state of superposition allows quantum computers to process a greater amount of information simultaneously compared to classical computers. For instance, a 4-qubit quantum computer can hold 16 different numbers at the same time, allowing it to perform multiple calculations simultaneously. This makes quantum computers potentially much faster than classical computers for tasks such as factoring large numbers or simulating quantum systems. When a quantum calculation is complete, measuring the qubits—which is needed to extract a usable result—“collapses” them to one value. Additionally, qubits can be entangled, a phenomenon where the state of one qubit is directly related to the state of another, no matter the distance between them.

A state of quantum entanglement between qubits is called coherence. Each qubit can hold many more values than a classical bit, and entanglement enables quantum computers to connect multiple qubits to perform operations on an exponentially larger set of data than classical computers and... These computers then provide ranges of possible answers to these operations, reducing calculation times greatly. Although quantum computers have great potential, building them is challenging. It is difficult for a quantum computer to maintain coherence among its qubits because of their interactions with the environment, a problem known as decoherence. Quantum computers must run at extremely low temperatures and use sophisticated error-correction techniques to keep qubits entangled long enough to perform calculations.

Moreover, measuring qubits to record a usable result can disturb their state, making it challenging to extract information at the right stage of the calculation without affecting the computation. Quantum computing is an emergent field of computer science and engineering that harnesses the unique qualities of quantum mechanics to solve problems beyond the ability of even the most powerful classical computers. The field of quantum computing includes a range of disciplines, including quantum hardware and quantum algorithms. While still in development, quantum technology will soon be able to solve complex problems that classical supercomputers can’t solve (or can’t solve fast enough). By taking advantage of quantum physics, large-scale quantum computers would be able to tackle certain complex problems many times faster than modern classical machines. With a quantum computer, some problems that might take a classical computer thousands of years to solve might be solved in a matter of minutes or hours.

Quantum mechanics, the study of physics at very small scales, reveals surprising fundamental natural principles. Quantum computers specifically harness these phenomena to access mathematical methods of solving problems not available with classical computing alone. Stay up to date on the most important—and intriguing—industry trends on AI, automation, data and beyond with the Think newsletter. See the IBM Privacy Statement. An official website of the United States government Official websites use .gov A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS A lock ( Lock A locked padlock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. https://www.nist.gov/quantum-information-science/quantum-computing-explained A computer that could break the encryption that safeguards your private information on the internet. A machine that can design powerful new drugs by precisely simulating the behavior of individual molecules. A device that optimizes complex supply chains to help companies get the parts they need and assemble them in the most efficient way possible.

For nearly a century, classical computing has fueled human progress. From the punch cards of the 1940s to the smartphones in our pockets, we’ve ridden the exponential wave of Moore’s Law—a doubling of transistor density every two years. But even the most intricate silicon chip, packed with billions of transistors, is running up against the limits of physics. At the smallest scales, classical logic starts to wobble. Electrons tunnel through barriers. Heat becomes unmanageable.

The world of bits begins to look… too simple. Nature, it turns out, doesn’t run on binary alone. At the subatomic level, reality doesn’t behave like a spreadsheet. It dances. It flickers between states. It interferes with itself.

It gets entangled. This is the world of quantum mechanics, and for decades it has both bewildered and inspired physicists. But now, out of the cloud of equations and paradoxes, something tangible is emerging—a machine built not just to simulate nature, but to embody it. Quantum computing is not just a faster calculator. It’s an entirely new way of thinking, one that mirrors the deepest truths of the universe. And as we stand at the edge of this frontier, the implications are nothing short of revolutionary.

To understand what makes a quantum computer different, we must first unlearn the tidy world of ones and zeroes. In a classical computer, every piece of information is encoded in bits—tiny switches that are either on (1) or off (0). These bits are strung together into longer sequences that represent letters, images, sound, software, and everything else in the digital age. Quantum computers can measure and observe quantum systems at the molecular level, as well as solve the conditional probability of events. Not to mention they can do billions of years worth of computing over the course of a weekend. Quantum computing is a process that uses the laws of quantum mechanics to solve problems too large or complex for traditional computers.

Quantum computers rely on qubits to run and solve multidimensional quantum algorithms. Quantum computing is vastly different from classical computing. Quantum physicist Shohini Ghose, of Wilfrid Laurier University, has likened the difference between quantum and classical computing to light bulbs and candles: “The light bulb isn’t just a better candle; it’s something completely different.” Quantum computing solves mathematical problems and runs quantum models using the tenets of quantum theory. Some of the quantum systems it is used to model include photosynthesis, superconductivity and complex molecular formations. To understand quantum computing and how it works, it’s necessary to first understand qubits, superposition, entanglement and quantum interference.

Access to this page requires authorization. You can try signing in or changing directories. Access to this page requires authorization. You can try changing directories. Quantum computing holds the promise of solving some of our planet's biggest challenges - in the areas of environment, agriculture, health, energy, climate, materials science, and more. For some of these problems, classical computing is increasingly challenged as the size of the system grows.

When designed to scale, quantum systems will likely have capabilities that exceed those of today's most powerful supercomputers. This article explains the principles of quantum computing, how it compares to classical computing, and how it uses the principles of quantum mechanics. Quantum systems, such as atoms and molecules, can be difficult or impossible to simulate on a classical computer. In the 1980s, Richard Feynman and Yuri Manin suggested that hardware based on quantum phenomena might be more efficient for the simulation of quantum systems than conventional computers. Quantum computers use quantum physics to access different computational abilities than classical computers. Google Quantum AI is exploring potential applications for cleaner fertilization, more efficient batteries, pharmaceutical discoveries, and more.

Classical computers have enabled some of humanity's greatest achievements. But even as classical computers continue to improve, there are certain problems we do not expect them to ever be able to solve. Because quantum computers use quantum physics to access new computational abilities that are inaccessible to classical computers, we expect that they will be able to solve some problems exponentially faster than classical computers can. In classical computing, information is stored in bits, which can take the value of either 0 or 1. Quantum computers use quantum bits (qubits) instead of bits. Those qubits take on richer states and extend beyond just 0 or 1 - they can be in a superposition, or a complex combination, of both 0 and 1.

With superpositionSuperposition is a property where a qubit takes the value of a complex combination of both 0 and 1. , we can explore an exponentially large space of possible solutions to a problem. Today's quantum processors are powerful enough to accomplish some contrived tasks more efficiently than the fastest classical supercomputers. But they still need to be improved to achieve their full potential. We call the current state of quantum computing the noisy intermediate-scale quantum (NISQ)While still at an early stage, NISQ era quantum computing holds the potential to explore some useful applications before fully error-corrected quantum... era.

Because noise plays a large role in the performance of NISQ devices, it's challenging to compare them to classical computers, which essentially work without error. We've developed a framework based on a circuit’s "effective quantum volume" to evaluate the computational cost of quantum circuits that can be run on today's noisy devices. Qubits are highly sensitive to their external environments, and even stray particles of light can introduce errors. For meaningful computation, these errors must be corrected, and error correction must be improved as quantum processors are scaled to larger numbers of qubits. We view the achievement of scalable error correction as a necessary step towards a truly useful quantum computer. Imagine a world where computers defy logic as we know it—where bits are no longer just…

Quantum computing is one of the most exciting technological advancements of our time, and at its… Image Credit: IBM Imagine a world where computers can solve problems that would take today’s supercomputers… Image Credit: IonQ Quantum computers are no longer just theoretical concepts—they are real and advancing rapidly…. Read More Price of a quantum computerContinue Flip a coin. Heads or tails, right?

What Is Quantum Computing Here S Everything You Need To Know Fast

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Qubits Can Exist In A Superposition Of States And Hold

A State Of Quantum Entanglement Between Qubits Is Called Coherence.

Moreover, Measuring Qubits To Record A Usable Result Can Disturb

Quantum Mechanics, The Study Of Physics At Very Small Scales,