Communication is the process of exchanging information usually via a common system of symbols. "Communication studies" is the academic discipline which studies communication.
Forms of communication
Forms and components of human communication
Humans communicate in order to share knowledge and experiences. Common forms of human communication include sign language, speaking, writing, gestures, and broadcasting. Communication can be interactive, transactive, intentional , or unintentional ; it can also be verbal or nonverbal. In addition, communication can be intrapersonal or interpersonal. There are a number of theories of communication that attempt to explain human communication.
In telecommunications, the first transatlantic two-way radio broadcast occurred on July 25th 1920.
As the technology evolved, communication protocol also had to evolve; for example, Thomas Edison had to discover that hello was the least ambiguous greeting by voice over a distance; previous greetings such as hail tended to be lost or garbled in the transmission.
As regards human communication these diverse fields can be divided into those which cultivate a thoughtful exchange between a small number of people (debate, talk radio, e-mail, personal letters) on the one hand; and those which disseminate broadly a simple message (Public relations, television, cinema).
Our indebtedness to the Romans in the field of communication does not end with the Latin root "communicare". They devised what might be described as the first real mail or postal system in order to centralize control of the empire from Rome. This allowed Rome to gather knowledge about events in its many widespread provinces.
As the Romans well knew, communication is as much about taking in towards the centre as it is about putting out towards the extremes.
In virtual management an important issue is computer-mediated communication.
The view people take toward communication is changing, as new technologies change the way they communicate and organize. In fact, it is the changing technology of communication that tends to make the most frequent and widespread changes in a society - take for example the rise of web cam chat and other network-based visual communications between distant parties. The latest trend in communication, decentralized personal networking , is termed smartmobbing.
Anxiety associated with communication is known as communication apprehension. Such anxiety tends to be influenced by one's self-concept. Besides apprehension, communication can be impaired via bypassing, indiscrimination, and polarization. Failing to share a common language is also an important barrier in many parts of the world.
Apart from that there may be following barriers in communication
- Time lag
 Dance, Frank. "The 'concept' of communication. Journal of Communication, 20, 201-210 (1970).