Brown lentils are by far one of the most popular types of lentils that can be found in the United States. Most grocery stores stock them, and they are a type of lentil that holds its shape very nicely once cooked. They have a mild and earthy flavor and can be used as a natural thickener when making veggie burgers or soup.
Green lentils are another popular type of lentil found in the USA. Their flavor is slightly spicy and they have a rather firm texture. However, they do unfortunately have the lengthiest cooking time out of all the varieties (about 40 minutes). These lentils are perfect as a warm side dish or in a French-style, too.
Red lentils are small split lentils that you can cook really quickly. They're commonly used in Middle Eastern, Mediterranean, and Indian dishes and become soft when cooked. This makes them ideal to use in soups, purées, and stews.
Yellow lentils are very similar to red lentils, however, they have a vibrant bright yellow color. They're nutty, sweet and only take around 15 minutes to cook. Yellow lentils are commonly used in certain Indian dishes, such as Yellow Lentil Dal with Curry.