Terminology
As with anything, there is a language to preserve-making that can be a little confusing.
However, here is a Rob's Preserves guide to understanding it all
Chutney
Indian in origin, this is traditionally made from fruit, spices and herbs and can take many forms.
Confit
Comes from the past participle of the French verb confire ("to preserve") and whilst this term can be applied to the preservation of meats, it can also apply to fruits or vegetables seasoned and cooked with honey or sugar until it resembles a jam. Savoury confits, such as those made with garlic or fennel, may call for an oil, such as virgin olive oil, as the preserving agent.
Jam
The term jam refers to a product refers to a product traditionally made of whole fruit cut into pieces or crushed. It is then heated with water and sugar until it reaches "jelling" or "setting" point, which is achieved through the action of natural or added pectin then sealed in containers such as jars.
Jelly
The term jelly comes from the French word 'gelee' and refers to a clear, translucent spread made traditionally from fruit made by a process similar to that used for making jam, with the additional step of filtering out the fruit pulp after the initial cooking.
Marmalade
The term Marmalade refers to any fruit preserve made from the juice and peel of citrus fruits boiled with sugar and water. It can be produced from any citrus fruits, or any combination. Marmalade is distinguished from jam by the inclusion of citrus peel, and the use of more water, in which respect it resembles a jelly. It is distinguished from a jelly by containing pieces of fruit peel. The benchmark citrus fruit for marmalade production in Britain is the bitter Spanish Seville orange (Citrus aurantium var. aurantium), which is highly prized for its high pectin content which enables a good set. The peel has a distinctive bitter taste which does not make it particularly pleasant to eat raw like other oranges. The origins of marmalade can be traced back to the Romans who learned from the Greeks that quinces slowly cooked with honey would "set" when cool. The Apicius gives a recipe for preserving whole quinces, stems and leaves attached, in a bath of honey diluted with defrutum (Roman marmalade). . Preserves of quince and lemon appear—along with rose, apple, plum and pear—in the Book of ceremonies of the Byzantine Emperor Constantine VII Porphyrogennetos
Pectin
Pectin is a natural gelling agent found in ripe fruit. Pectin is an important ingredient in making jams and jellies. The levels of pectin vary from fruit to fruit. Some fruits, such as citrus fruit, blackberries, apples and redcurrants, have high pectin levels whilst tropical and peak summer fruit such as cherries, strawberries, pears, peaches, and rhubarb tend to be low in pectin requiring jam or preserving sugar to be added to the preserve to enable a good set. Other berries like blueberries, raspberries, and blackberries are somewhere in the middle in terms of their pectin levels..