using vh and vw css code example

Example 1: vh vs vw css

vh and vw measure the percentage of height and width of the viewport respectively.
 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

Example 2: what is css vh

CSS VH unit Property
Viewport Height ( vh ) 
– A percentage of the full viewport height. 10vh will resolve to 10% of the current viewport height. Viewport Minimum ( vmin ) 
– A percentage of the viewport width or height, whichever is smaller.