Quantum is a discrete amount of energy. In Physics you think of electrons occupying different quantum levels. To make a "quantum jump" from one level to another higher level the electron must gain extra energy to rise to this next level.
This Physics term has entered our common language to mean a sudden dramatic change in thought, deed or invention.
The discovery of penicillin was a quantum leap in the fight against infectious disease.
"Look at my rent for this apartment now!!! It's a quantum leap from where it was last month! I don't know how I will manage to live here on my fixed income."
Student or Learner