Attachment as a book publishing and reading term has two distinct but related meanings. As a book publishing term, attachment refers to the practice of including with a book an item that is not part of the book itself but which the publisher believes will increase sales of the book. Items commonly attached to books include bookmarks, postcards, stickers, and other collectibles. In this context, attachment is a marketing tool intended to make a book more appealing to potential buyers.
In computing, It is a file attached to an email message. The most common type is a document, but it can be any type of file, including a picture, video, or audio file.
These are often used to send files too large to be sent as email attachments. For example, if you want to send a video clip that is too large to be sent as an email attachment, you can upload it to a file-sharing site and then send a link to the file in your email.
Attachments can also be used to send virus-infected or otherwise dangerous files. In these cases, sending the file as an attachment is best rather than sending it as an email attachment.
Some email programs limit the size of attachments, so it is important to check the file size before sending it as an attachment. If the file is too large, you may need to compress it or split it into smaller files.
They can be opened by clicking on the icon in the email message. The file will then be downloaded to your computer. Once the file is downloaded, you can open it using the appropriate software.
Some email programs allow you to preview them without downloading it. This can be useful if you want to see what the attachment contains without downloading it.
If you receive one that you do not recognize or think may be harmful, do not open it. Instead, delete the email message without opening the attachment.