Electronic mail, most commonly called email or e-mail since around 1993, is a method of exchanging digital messages from an author to one or more recipients. Email operates across the Internet or other .
Conversation threading is a feature used by many email clients, , , and in which the software aids the user by visually grouping messages with their replies. These groups are called a conversation, topic thread, or simply a thread. A discussion forum, e-mail client or news client is said to have a "conversation view", "threaded topics" or a "threaded mode" if messages can be grouped in this manner.
A shopping mall is a modern, chiefly North American, term for a form of shopping precinct or shopping center, in which one or more buildings form a complex of Retailing representing merchandisers with interconnecting that enable customers to walk from unit to unit. A shopping arcade is a specific form serving the same purpose.