I'm making a website now, and to be honest I'm not really a designer. Currently the site I'm making does not have a fixed header, and I'm not sure if I should make it fixed or not. A lot of sites I use do not have a fixed header, but I see the potential and use of it.

My question for you: What do you think of fixed headers on websites? Does it make the website easier to use, or do you think it's waisted space? Or do you think it's useful but only when you're on a certain device?