Headings are second-generation headlines, words or phrases that introduce sections of a piece of content and thus help a writer organize the content into smaller components. This post describes three categories of headings and their functions. Headings are second-generation headlines, words or phrases that introduce sections of a piece of content and thus help a writer organize the content into smaller components. This post describes three categories of headings and their functions. Headings are second-generation headlines, words or phrases that introduce sections of a piece of content and thus help a writer organize the content into smaller components. This post describes three categories of headings and their functions. Headings are second-generation headlines, words or phrases that introduce sections of a piece of content and thus help a writer organize the content into smaller components. This post describes three categories of headings and their functions.