What does the 'font-family' property do in CSS?

The 'font-family' property in CSS is essential for controlling the appearance of text by specifying which typeface or font should be used for rendering the text in an element. This property allows web designers to choose from various fonts, which can include system fonts, web-safe fonts, or custom fonts loaded via @font-face or other methods. When the 'font-family' property is applied, it directly affects the overall look and feel of the text, ensuring that it aligns with the design goals of the website.

For instance, if a designer sets the 'font-family' to 'Arial', all text within that element will be displayed using the Arial font, providing a consistent and specific visual style. By specifying multiple font choices, separated by commas, designers can also create fallbacks, ensuring that if the preferred font is unavailable, a secondary option is used. This capability to customize the typeface enhances readability and user experience across different devices and browsers.