Junk mail'%2C often referred to as 'spam'%2C is a term used to describe unsolicited commercial emails or advertisements sent in bulk to a large number of recipients. The term 'junk mail' is also used to describe unwanted physical mail such as flyers%2C catalogs%2C and postcards. The acronym ADS refers to the term 'ADVERTISING' which is the practice of promoting a product or service through various forms of media.