THERE ARE TWO TYPES OF GRIDS USED IN PAGE LAYOUT: column grids and base-line grids. Column grids determine the way the page is divided vertically. Baseline grids determine how the page is divided horizontally. It is common to use both types of grids together.
Grids define where the different elements of your document are placed on the page. Essentially they are visual aids to help you quickly and consistently arrange text and graphics on a page. They come in all shapes and sizes, and there are different strategies for using them. Beneath just about every well-designed document is a grid of some sort. Novels use a simple one-column grid, but even this has to be carefully considered, because it will determine the type area of the page as well as where the folios go. Newspapers and magazines with multiple columns and a mixture of type sizesas well as photographs and illustrationscall for a more complex grid that combines a flexible number of columns with a baseline grid.
To the average reader, a well-designed grid will be invisible; nevertheless it's there, helping the reader to make sense of all the different elements in a document. Columns of text, headlines, photos, illustrations, captions, pull quotes, and other page elements are more easily tied-togetheror unifiedon the page that is based on a grid. To the designer, grids enhance creativity by imposing structure. Because they take a lot of the guesswork out of your design, grids significantly speed up workflow.