Geography

Geography (Greek Geo (γη) or Gaea (γαία), meaning “Earth”, and graphein (γράφειν) meaning “to describe” or “to write”) is the study of the earth and its features, inhabitants, and phenomena. A literal translation would be “to describe or write about the Earth”. The first person to use the word “geography” wasEratosthenes (275-195 B.C.). Four historical traditions in geographical research are the 

Protocol data unit

In telecommunications, the term protocol data unit (PDU) has the following meanings:Information that is delivered as a unit among peer entities of a network and that may contain control information, address information, or data.In a layered system, a unit of data which is specified in a protocol of a given layer and which consists of protocol-control informationand possibly user data of that