A simplified explanation of Planck’s constant:
Imagine that you are pouring water into a pan, and you discover that, rather than flowing as a continuous stream, the water was actually composed of droplets so small that they looked like a stream. No matter how fast or slowly you poured, the water always came out in droplets.
So you tried to pour out as little water as you could, to see if you could get a half of a droplet, or a quarter-droplet, etc. What you find is that tipping out the water, either none comes out, or a single droplet, or multiples of that single droplet. So it turns out that water has a minimum sized droplet that can be poured out. So we’d like to measure the size of that droplet, so that I can now describe the amount of water poured out in terms of the number of droplets.
Now, this is not true for water (unless we are talking water molecules themselves). But it IS true for energy. Energy can only be released or absorbed in “droplets” (known as “quanta”). And Planck’s constant helps describe the minimum size those “droplets” of energy can be.
Make sense?
Are you confusing Planck’s Constant with The Plank Length?