What is the meaning of Attachment?

The act or process of (physically or figuratively) attaching.

A strong bonding with or fondness for someone or something.

A dependence, especially a strong one.

A device attached to a piece of equipment or a tool.

The means by which something is physically attached.

A file sent along with a message, usually an email.

Taking a person's property to satisfy a court-ordered debt.

The act or process by which any (downward) leader connects to any available (upward) streamer in a lightning flash.

attachment (to an email)

attachment, personal bonding

Source: wiktionary.org