Paizo's Starfinder system is heavily based on their long-running Pathfinder system (itself based on D&D 3.5). What rules are different between the two systems?
To clarify, this question does not cover changes to content (individual skills, classes, races, feats, etc). Changes to how those components work or are acquired are relevant. This question also does not cover new rules systems in Starfinder, such as spaceship construction and combat, as there are no equivalent Pathfinder rules to compare to.
I'm aware that some Pathfinder rule components have been renamed in Starfinder; these should only be included in answers if their functionality has also changed.
A detailed explanation of each difference isn't necessary; a quick bullet point along the lines of, "A full attack in PF is a number of attacks based on your BAB while in SF it's 2 attacks at -4," is sufficient.