profic = the belief that anyone can write anything they want, however they want, when it comes to fiction, even if it's about something taboo, and that no one deserves to be shamed, harassed or have their works censored.
proship = the belief that anyone can ship any fictional characters they want together—even if it would have been taboo or socially unacceptable if it were real life—because it's fiction and fantasies. and no one deserves to be shamed or harassed over fiction.
both profic and proship also hold the belief that if, in fandom space, fancontent bothers, upsets or triggers you, the right thing to do would be to scroll past/block/mute/filter out what you don't want to see and curate your own internet experience, instead of harassing or shaming real people over fiction.
(therefore people who are profic/proship can absolutely have things they are uncomfortable with—they don't just "like every single taboo thing" which is a common misunderstanding—but they choose to curate their own internet experience by ignoring/blocking/muting what they don't want to see and let people do whatever they want, as long as no one in real life is being harmed, instead of harassing real people over fiction.)
both profic and proship do overlap a lot and they can often be used interchangeably.
more here and here
