Earlier Traditional communication services such as postal service(Snail mail) are used for communication. It is a low speed and not reliable service. In order to increase the speed Telegram Services were used. Its speed was high but it has lot of limitations and expensive too. Later telephones were used for voice communication.
Nowadays telephone system and computer system are integrated and create a virtual(unreal) environment. This is called cyber space. The result for this integration is that tremendous speed and it is very cheap.
