A baseline is the line where text sits. A baseline grid is a secondary type of grid that sits within every grid and helps designers to give a flowing rhythm to the text.

The baseline grid contributes to the visual hierarchy, particularly when it comes to typography. Elements that take up more rows on the baseline grid (like headings and subheadings) have more visual weight and are viewed as more important.^[1]

Most designers stick to an 8-point baseline grid and use multiples of 4px for more precise adjustments in spacing or line height.