What is a quantum computer?
A quantum computer is a machine that computes with qubits, which can hold a combination of 0 and 1 at the same time and can be linked so that their states depend on each other. For most tasks it is no faster than an ordinary computer. For a few problems with the right mathematical structure, a quantum algorithm makes the wrong answers cancel out and the right one stand out, and that gives an enormous speed-up. Today's machines have too few qubits and too many errors to threaten encryption. Breaking it would need a large, fault-tolerant machine that corrects its own errors, which nobody has built yet. For your company the practical point is narrow: such a machine would break the public-key cryptography that protects almost every connection you make, so the replacement has to be planned before it exists.