The baseline grid represents the leading for body text in a document. You can use multiples of this leading value for all elements of the page to ensure that text always lines up between columns and from page to page. For example, if the body text in your document has 12‑point leading, you could give your heading text 18‑point leading and add 6 points of space before the paragraphs that follow the headings.

Using a baseline grid ensures consistency in the location of text elements on a page. You can adjust the leading for the paragraph to ensure that its baselines align to the page’s underlying grid. This is useful if you want the baselines of text in multiple columns or adjacent text frames to align. Change settings for the baseline grid by using the Grids section of the Preferences dialog box.

You can also align only the first line of a paragraph to the baseline grid, allowing the rest of the lines to follow the specified leading values.

To view the baseline grid, choose View > Grids & Guides > Show Baseline Grid.