What does the term "sebum" refer to?

The term "sebum" refers specifically to the natural oils produced by the sebaceous glands in the skin. These oils play a crucial role in maintaining the health of the skin and hair by providing moisture, protecting against environmental damage, and preventing infection. Sebum also helps to keep the skin barrier intact, making it essential for overall skin health.

Understanding the properties of sebum is fundamental for anyone in the cosmetology field, as it directly influences hair and skin care practices. For instance, products that aim to balance oil levels on the skin or scalp often take sebum into account. This knowledge helps professionals make informed choices about treatments and products suitable for individual clients based on their skin types and conditions.

The other options describe different concepts related to skincare but do not accurately define sebum, which is why they do not apply in this context.