I wanted to ask if centimeters on websites are always the same for everyone. I read somewhere that pixels are getting displayed different based on your current hardware. If I have an A4 page for instance on my website, and I want users to print it out, will every user with different hardware specs get the very same results?
If you want to print text you should use "em, cm, mm, in, pt, pc, %" . These units come from typographia, they have absolute measures.
On the other hand "px" doesn't act like a constant but depends on hardware, you can learn more at : https://www.w3.org/Style/Examples/007/units.en.html .