Quantum Computers Are Devices That Manipulate Quantum Bits, Or Qubits. But Instead Of Using A Transistor To Perform This Function, Quantum Computers Directly Encode This Information Onto Elementary Particles Like Electrons And Photons, Even Entire Atoms.

Light-Based Quantum Computer Exceeds Fastest Classical Supercomputers. A Quantum Computer Made From Photons—Particles Of Light—Has Outperformed Even The Fastest Classical Supercomputers. ... More Broadly, The Ability To Control Photons As Qubits Is
A Prerequisite For Any Large-Scale QUANTUM INTERNET...
Quantum Technology Is Often Divided Into Four Areas: Quantum Computing, Quantum Simulation, Quantum Communica​tion And Quantum Sensing.

... This Means That A Quantum Computer With 300 Qubits Would Be Able To Represent
More Values Than There Are Particles In The Entire Universe.​