Charts? What are they?

ETA: Actually - I'll add to my post LOL - when we were in hospital with Kayla being prem, everything was scheduled and charted and I had to keep reminding myself that once we're out of the hospital we won't be worrying about all this! Timed feeds, strict weight gains etc etc etc. I can only imagine the pressure of CHN's constantly sticking to those horrible charts and the effect it must have on new mums. I say 'imagine' because as a rule I don't go to CHN's LOL - haven't found one that tells me what I want to hear