Bread is a food essentially made from flour, water and salt that has been kneaded, allowed to rise, shaped or molded, and baked in the oven. Bread can contain a fermenting agent that makes it rise (a sourdough starter or yeast), or have none, in which case it is an unleavened bread (such as the Middle Eastern "pita" or the Indian "chapati," etc.).
A bread roll is a piece of bread, usually small and round and is commonly considered a side dish. Bread rolls are often used in the same way as sandwiches are—cut transversely, with fillings placed between the two halves
Ingredients: The essential ingredients used in bread include flour, salt, yeast and water. Optional ingredients are sugar, milk, fruit, fat, and milk products.
Flour: Flour is the primary ingredient of any bread recipe. Flour contains gluten, a protein that provides for the elasticity and the basic structure of bread. Strong flour containing 12 to 14 per cent gluten is preferred for bread making. Although wheat flour is the most commonly used flour for making bread, non wheat flours like millet and rye can also be used. However, since the latter types do not have gluten, they must be mixed with large amounts of wheat flour.
Yeast: In presence of water, yeast cells use sugar present in the flour and release carbon dioxide gas which rises when heated. The gluten present in flour makes the dough elastic.
Salt: Salt allows the baker a control over the rising of bread. This it does by strengthening gluten in flour. As it slows down the rising process of bread, salt allows the dough to develop flavor.
Water: Water helps to combine all the ingredients together. It also aids in activating yeast that releases carbon dioxide.