Almost every layout has axes, invisible lines along which key elements — like text blocks, headlines, and illustrations — are arranged. These guidelines are the basic elements of the grid.
A grid can be very primitive and, for a book with a simple structure, may serve mostly as the baselines and margins of the text. Or it can be very complex, like when dealing with the variety of texts, headlines, photos, announcements and graphics that make up a newspaper. In a multi-column magazine, the number of columns in the grid may unexpectedly change from section to section.
On a website, it may extend or compress in response to the width of the browser.
