A memorandum or memo is a document or other communication that helps the memory by recording events or observations on a topic, such as may be used in a business office. Letters
A commercial business letter is a letter written in formal language, usually used when writing from one business organization to another, or for correspondence between such organizations and their customers, clients and other external parties. E-mail
An email message consists of three components, the messageenvelope, the message header, and the message body. The message header contains control information, including, minimally, an originator's email address and one or more recipient addresses. Usually descriptive information is also added, such as a subject header field and a message submission date/time stamp. Video Conference
A videoconference or video conference (also known as a videoteleconference) is a set of interactivetelecommunication technologies which allow two or more locations to interact via two-way video and audio transmissions simultaneously. Fax
A fax (short for facsimile) is a document sent over a telephone line. Fax machines have existed, in various forms, since the 19th century, though modern fax machines became feasible only in the mid-1970s as the sophistication of technology increased and cost of the three underlying technologies dropped. Businesses usually maintain some kind of fax capability, the technology has faced increasing competition from Internet-based alternatives. However, fax machines still retain some advantages, particularly in the transmission of sensitive material which, if sent over the Internet unencrypted, may be vulnerable to interception, without the need for telephone tapping. In some countries,...