Muslin is a type of cotton fabric characterized by a plain weave. It ranges widely in weight from very thin, delicate sheers to coarser types used for sheeting. Muslin is traditionally made from cotton fibers and is known for its lightweight, breathable, and soft texture. Historically, muslin was famously produced in the Bengal region (present-day Bangladesh and India) and was highly prized for its fine quality and transparency. Cotton is the natural fiber that muslin is typically made from. It refers more broadly to the fluffy fiber harvested from cotton plants, which can be spun and woven into many types of fabric, including muslin. Cotton itself is known for being soft, breathable, and absorbent, which are qualities imparted to muslin fabrics. In summary:

• Muslin is a specific fabric made typically of cotton, defined by its plain weave and range of textures from sheer to coarse.
• Cotton is the natural fiber used to make muslin and many other fabrics.
• Muslin can be considered a cotton fabric but with particular characteristics in weave and weight.

Muslin thus represents a category of cotton fabric notable for its breathability, softness, and lightweight properties, often used for clothing, bedding, and other textile products.