Dietary fiber refers to plant-based carbohydrates that are not digestible by humans. It is an essential component of a healthy diet and is known to aid in digestive health. There are two main types of fiber: soluble and insoluble. Soluble fiber dissolves in water to form a gel-like substance, helping to lower blood cholesterol and glucose levels. Insoluble fiber, on the other hand, promotes the movement of material through the digestive system and increases stool bulk.