All digital information (images, text & video) today is represented by a combination of zeros ("0") and ones ("1") - each of them called a bit. In a conventional computer chip, these bits are represented by release and capture of electrons (i.e. charge). Transistors and logic circuits inside the chip use electrical voltage to change bits.

Quantum computers, on the other hand, represent a bit differently. Instead of using the electron charge, they use the electron "spin" - its quantum property, as a qubit (quantum bit). Every electron is known to have 2 spin states; spin-up and spin-down. Depending on its present state, a qubit can be either 0 or 1.

However, quantum physics allows an electron to exist in both its spin states simultaneously - so it can be 0 and 1 at the same time! Additionally, spin states of different electrons can be linked together in a way that change in one qubit automatically leads to change in the others. These quirky quantum properties offer unique ways to perform faster calculations.

Some research teams have already demonstrated quantum computing up to 128 qubits. As the number of qubits increase, preserving and controlling their quantum properties become difficult. Scientists are tackling these challenges to make quantum computers a reality in the near future.