Source Sans

Source Sans (known as Source Sans Pro before 2021) is a sans-serif typeface created by Paul D. Hunt, released by Adobe in 2012. It is the first open-source font family from Adobe, distributed under the SIL Open Font License. The typeface is inspired by the forms of the American Type Founders' gothics by Morris Fuller Benton, such as News Gothic, Lightline Gothic and Franklin Gothic, modified with both a larger x-height and character width and more humanist-influenced italic forms. It is available in seven weights (Regular, ExtraLight, Light, Medium, Semibold, Bold, Black) in upright and italic styles, and is also available as a variable font with continuous weight values from 200 to 900. The typeface has wide language support for Latin script, including Western and Eastern European languages, Vietnamese, pinyin romanization of Chinese, and Navajo.

From the Wikipedia article “Source Sans”, licensed under CC BY-SA 4.0.

Sans-serif faces work well for headings, captions, children's books and modern nonfiction. For long-form body text in print, most designers still prefer a serif.

Commercial typefaces require a licence that covers embedding in PDFs and ebooks; check the foundry's licence before you publish.