This article is from the Food Preserving FAQ, by Eric Decker firstname.lastname@example.org with numerous contributions by others.
These are templates which can give you ideas for unusual gifts, or
really unusual jams and jellies. Fruity,cannable things 101 as taught by
Barb Shaller, Famed Fruit Spread Preserver.
Preserves: The broad category AND a specific product: Whole
fruits (or similar-sized cut pieces of fruit too large to be done whole)
preserved in a thick sugar syrup varying in viscosity from that of honey to
soft jelly, so that the fruit retains its shape.
Jelly: The jelled *juice (only)* of the fruit or vegetable. A prize-winning
one will be clear, lacking crystallization, and will be firm enough to hold
its shape outside the jar, yet will be soft enough for easy spreading.
Jam: Will contain fruit bits. Fruit prepared for jamming is typically crushed
or chopped and cooked with sugar. Pectin may be added to assist the jel. A
little softer than jelly.
Butter: The smooth pureed pulp of the fruit, cooked and sweetened until very
thick. Often enhanced with sweet spices. Must be cooked slowly. Refer to FAQ
for sad stories and a couple good recipes [look down :)--LEB].
[ The very best butters are made with nothing but the fruit. Slow cooked over
many hours - one MUST keep stirring constantly - an exquisite flavour is
derived - ED
Conserves: Jam-like combinations of two or more fruits,
traditionally without added pectin and traditionally containing nuts and
raisins. YMMV. A good one is on the soft side.
Marmalades: Soft fruit jellies, typically citrus products, containing small
pieces of fruit or peel evenly suspended in the transparent jelly. Good
definitions from the Ball Blue Book.