Margin in typography refers to the space around the edges of a page or a block of text. It's like having a playground around the text where no other words or things go, just like how you have a space around your coloring page to make sure you don't color outside of the lines.
Margins help make the text more readable by adding open space that separates text from other elements like pictures or graphics. Without margins, the text would run all the way to the edge of the page, making it hard to read.
Margins also help with design. When you want to make a document or a book page look pretty, margins can make a big difference. For example, if you want to create a greeting card, you need to have enough margin for a border so that the message doesn't go all the way to the edge of the card.
So, margins are like the breathing space for text. They make the text more legible and create a great design for books, documents, and greeting cards.