Margins are the blank spaces around the edges of a document. They can be used to create a border around the text, or to make the text easier to read by providing white space around it. In Google Docs, you can easily set the margins to 1 inch all around.
There are several reasons why you might want to set the margins to 1 inch. One reason is that it is the default margin setting for many printers. This means that if you print a document with 1-inch margins, it will likely print correctly on most printers. Another reason to use 1-inch margins is that it can make your document look more professional. Wider margins can give your document a more polished and finished appearance.