Jam is a sweet, thick concoction made from crushed fruit. Jelly is made from the clear juice of fruit or other things. Marmalade is a jam with bits of citrus peel included. Conserve is usually made with two or more fruits and with raisins and nuts sometimes added. Molasses is made from sorghum juice.
Corn syrup is made from corn sugar.
Maple syrup is made from the sap of the Maple tree. Only preservation societies deal with making syrup now days so we will deal with the jams and jellies. Texas pioneers found native fruits that they made into preserves. Wild mustang grapes were and are still popular for jelly. They also make a killer wine in the right hands.