Imagine you have a really cool game on your phone where you can collect points. Each point in the game is the smallest possible unit of score you can earn. You can't earn half a point or a quarter of a point; you can only earn whole points, one at a time. 

Let's think about the world at the tiniest scales, where atoms and particles like electrons live. Scientists discovered that, just like your game points, certain things in nature come in the smallest possible units. These tiny units are called "quanta" (the plural form of "quantum"). 

For example, let's talk about light. Light can be thought of as being made up of tiny packets of energy called photons. Each photon is like a single point in your game – it's the smallest piece of light energy you can have. You can't have half a photon or a third of a photon; you can only have whole photons. 

Another example is electrons in an atom. We can imagine an atom like a solar system, with the nucleus and electrons orbiting around it. The electrons can only be in specific orbits or energy levels, like your game points. They cannot be between these orbits, just like you cannot earn a fraction of points in the game.  

So, when we use the word "quantum," we're talking about these tiny, indivisible units of something – whether it's light, energy, or even other properties like the position or momentum of a particle. This idea is called “quantization,” a key of quantum mechanics, a branch of science that studies how things work at the smallest scales in the universe. Quantum mechanics tells us that things at the smallest scale don't work like they do in our everyday world. Instead of being smooth and continuous, they come in tiny, fixed units. 

So, when we talk about "quantum," we're talking about the idea that certain properties, like the energy of light, can only exist in specific, discrete amounts, much like the smallest point you can earn in your favorite game. 

Niels Bohr, one of the founders of Quantum Mechanics said  

So, it is okay to be puzzled by the world of quantum! With the advancement of quantum computing and other technologies, now is the time to dive into the world of Quantum, and you can find them around you!  

“Those who are not shocked when they first come across quantum theory cannot possibly have understood it.”