The primary ingredient in jam is fruit. Jam is a spread made by cooking down fruits with sugar and often pectin, a natural thickening agent. The most commonly used fruits include strawberries, raspberries, blueberries, and cherries, among others. The process involves mashing the fruit, cooking it with sugar until it reaches the desired consistency, and then canning it for preservation. Jam is enjoyed as a sweet topping for bread, toast, pastries, and various desserts, making it a popular choice for adding flavor and enjoyment to many meals.