# QUANTUM COMPUTING - AN IN-DEPTH (02)

Updated: May 9

Quantum computing is a beautiful fusion of quantum physics with computer science. It incorporates some of the most stunning ideas of quantum physics from the twentieth century into an entirely new way of thinking about computation. The basic unit of quantum computing is the** Qubit**.

**We will learn what qubits are and what happens when we measure them. A classical bit is either 0 or 1. If it’s 0 and we measure it, we get 0. If it’s 1 and we measure 1, we get 1. In both cases the bit remains unchanged. The situation is totally different for qubits. A qubit can be in one of an infinite number of states—a superposition of both 0 and 1—but when we measure it, as in the classical case, we just get one of two values, either 0 or 1. The act of measurement changes the qubit.**

A simple mathematical model describes all of this precisely. Qubits can also be entangled. When we make a measurement of one of them, it affects the state of the other. Again, this is something that we don’t experience in our daily lives, but it is described perfectly by our mathematical model.

**Why Quantum Computing is so important?**

Until now, we’ve relied on supercomputers to solve most problems. These are very large classical computers, often with thousands of classical CPU and GPU cores. However, supercomputers aren’t very good at solving certain types of problems, which seem easy at first glance. This is why we need quantum computers (or computing).

*In the next blogs, we will understand the basic ideas that underlie quantum computing and we'll also see some ingenious and beautiful constructions.....*