What is CSS px unit?

Pixels (px) are fixed-size units that are commonly used in screen media. One pixel is equal to one dot on the computer screen.

20px

Frequently Asked Questions about px units

Is a CSS pixel the same as a device pixel?
No, a CSS pixel (px) is an abstract unit that may not correspond exactly to physical screen pixels, especially on high-DPI displays.
When should I use px?
Use px for precise sizes that should remain consistent across devices, like borders or small decorative elements.