The first picture shows some blocks leading aft from the vicinity of
the mast, ending up at a cleat. Question is, what are they used for?
Difficult to say with out knowing more about how the boat is rigged out
and the sails. Frequently that kind of setup is used to bring halyards
aft to the cockpit or some other sail control like a downhaul, outhaul,
boom vang, etc. Also possible but less likely in my opinion is that
they could be for jib sheets.

The winch in the second picture is almost certainly for the jib sheets.

halyard: raises sail up the mast and holds it in position.

sheet: controls lateral position of sail (trim).