To attach file means to include or add a document, image, or other digital file to an email, message, or online platform. This action allows the recipient to access and view the attached file, which can be anything from a simple text document to a complex multimedia presentation. Attaching files is a common and convenient way to share information and collaborate with others, making it an essential feature in modern communication. It is often represented by a paperclip icon, symbolizing the act of physically attaching a document to a piece of paper. With the ability to attach files, individuals and businesses can easily exchange important information and ideas, making it an integral part of our digital world.