Non-keratinized refers to a type of epithelial tissue that lacks the tough, protective protein called keratin. This type of tissue is typically found in areas of the body that require flexibility and moisture, such as the lining of the mouth, esophagus, and vagina. Non-keratinized epithelium helps protect underlying tissues while allowing for absorption and secretion. Unlike keratinized tissue, which forms a barrier against environmental damage, non-keratinized tissue remains soft and pliable. This characteristic is essential for functions like swallowing and reproduction, where movement and moisture are crucial. The presence of non-keratinized epithelium plays a vital role in maintaining the health of these organs.