A DMCA Notice is a notice that a person or company can send to another who has been using their copyrighted content without their permission. The notice tells the infringer to take the copyrighted content down...

DMCA Takedown can refer to the actual taking down of the content, or to the entire process of initiating a takedown of content that originally belongs to you and is used without your permission.

A DMCA Complaint is a complaint that is submitted against another person or entity who is using copyrighted content that belongs to someone else.