Final answer:
Epithelial tissue, also known as epithelium, covers and protects body surfaces and lines body cavities. It serves to protect the body and carries out various functions such as absorption, transport, and secretion.
Step-by-step explanation:
Epithelial tissue, also referred to as epithelium, refers to the sheets of cells that cover exterior surfaces of the body, line internal cavities and passageways, and form certain glands. It serves primarily as a covering or lining of body parts, protecting the body, and also functions in absorption, transport, and secretion.