Exchange of information through the use of speech, signs or symbols is called communication. When early humans started speaking, some 5,00,000 years ago, that was the first mode of communication. Before we dive into modern technologies that drive communication in contemporary world, we need to know how humans developed better communication techniques to share knowledge with each other.
Communicating with people over a distance is known as telecommunication. The first forms of telecommunication were smoke signals, drums or fire torches. The major disadvantage with these communication systems was that only a set of pre-determined messages could be transmitted. This was overcome in the 18th and 19th century through development of telegraphy and Morse code.
Invention of telephone and establishment of commercial telephony in 1878 marked a turnaround in communication systems and real telecommunication was born. International Telecommunication Union (ITU) defines telecommunication as transmission, emission and reception of any signs, signals or messages by electromagnetic systems. Now we had the communication technology to connect with people physically located thousands of kilometers away.
Telephones slowly gave way to television, videophone, satellite and finally computer networks. Computer networks have revolutionized modern day communication and communication technologies. That will be the subject of our in-depth study in subsequent chapters.