Okay, imagine you are looking at a really big and beautiful picture. This picture is made up of thousands of tiny little dots called pixels. The more pixels there are, the clearer and more detailed the picture will be.
Now, 16k resolution means that there are 16,000 pixels across the width of the picture. That's a LOT of pixels! So, if you were looking at a 16k picture, you would be able to see every little detail in it, like individual blades of grass or even the tiniest wrinkles on someone's face.
It's kind of like looking through a really, really strong magnifying glass. But instead of just seeing things closer, you see them in much greater detail than you normally would.
So, in summary, 16k resolution means a picture that is made up of 16,000 pixels across the width, which makes it incredibly clear and detailed.