[2021] What Does Player Experience Per Specialty Actually Do?

Hi there im a bit confused about what exactly this does im trying to set this up with a couple of my friends. If im understanding this correctly anytime i advance one of my skills mining etc. Then i should get experience? Will this also disable the system with gaining xp per day with housing? And what does setting the value of it have to do with anything (surely 1 would just enable it but it goes further than that). Can someone elaborate or help me understand what exactly this does. Thanks in advance!