Cách sử dụng
A header is a part of a document, like a piece of paper or an online page, that appears at the top. It usually contains important information such as the title of the document, the author's name, the date it was created, and sometimes a logo or picture. A header is commonly used in professional and academic writing, as well as in website design. Its purpose is to provide a quick way for readers to identify the document and its contents without having to read through the entire document.