Funny that the Phoenicians, who had a perfectly serviceable F decided to spell it with a P-H. Their F historically represented a hook on the end of a staff and made a sound like a V. Of course in english we haven’t rid ourselfes ov making the two letters interchangeable for the sounds.
Careful not to confuse ‘long s’, ſ, for lowercase f, as many people, and most OCR programs do. Long s often has a lead-in stroke, but never has a crossbar. The character fell out of disuse starting in the late 18th century. Unless you’re typesetting a historical or period work, you may never touch one.