In the context of makeup application, what does the term 'primer' refer to?

The term 'primer' in makeup application refers to a base product designed to enhance the longevity of makeup. Primers are applied before foundation and other makeup products to create a smooth canvas for application. They help to fill in pores, reduce the appearance of fine lines, and can also control oil or improve the skin's texture, which leads to a more even and lasting finish. The primary function of a primer is to ensure that the makeup adheres better to the skin and lasts longer throughout the day, providing a more polished look.

The other options refer to different categories of makeup products. A finishing product for setting makeup is typically a setting spray or powder that is used after makeup has been applied to lock it in place. Cleansing products are used to remove makeup, and a product for adding color would generally refer to items such as blush, lipstick, or eyeshadow, which are meant to enhance the color on the face rather than serve as a base.