I just learned about a new and uncommon CSS unit. vh and vw measure the percentage of height and width of the viewport respectively.
I looked at this question from Stack Overflow, but it made the units look even more similar.
How does vw and vh unit works
The answer specifically says
vw and vh are a percentage of the window width and height,
respectively: 100vw is 100% of the width, 80vw is 80%, etc.
This seems like the exact same as the % unit, which is more common.
In Developer Tools, I tried changing the values from vw/vh to % and viceversa and got the same result.
Is there a difference between the two? If not, why were these new units introduced to CSS3?