Crouton

A crouton is a piece of rebaked bread, often cubed and seasoned. Croutons are used to add texture and flavor to salads—notably the Caesar salad—as an accompaniment to soups and stews, or eaten as a snack food. 
Etymology.
The word crouton is derived from the French "croûton", itself a diminutive of "croûte", meaning "crust". "Croutons" are often seen in the shape of small cubes, but they can be of any size and shape, up to a very large slice. Many people now use crouton for croute, so the usage has changed. Historically, however, a croute was a slice of a baguette lightly brushed with oil or clarified butter and baked. In English descriptions of French cooking, "croûte" is not only a noun but also has a verb form which describes the cooking process that transforms the bread into the crust.
Preparation.
The preparation of croutons is relatively simple. Typically the cubes of bread are lightly coated in oil or butter (which may be seasoned or flavored for variety) and then baked. Croutons can also be cut into sticks. Some commercial preparations use machinery to sprinkle various seasonings on them. Alternatively, they may be fried lightly in butter or vegetable oil, until crisp and brown, to give them a buttery flavor and crunchy texture. Some croutons are prepared with the addition of cheese.
Nearly any type of bread—in a loaf or pre-sliced, with or without crust—may be used to make croutons. Dry or stale bread or leftover bread is usually used instead of fresh bread. Once prepared, the croutons will remain fresh far longer than unprepared bread.
Gastronomy.
A dish prepared "à la Grenobloise" (in the Grenoble manner) has a garnish of small croutons along with beurre noisette, capers, parsley, and lemon.
Dried and cubed bread is commonly sold in large bags in North America to make Thanksgiving holiday stuffing or dressing, although these are generally different from salad croutons, being only dry bread instead of buttered or oiled and with different seasonings, if any.
References.
https://crouton.net/