An important part of world history is the story of communication. In prehistoric times, for example, people did not have books. They did not know much about geography. People were limited. They knew only about themselves and their environment (the land around their homes). Their knowledge of geographical things like mountains and rivers was limited. They did not travel very far. Sometimes they knew about nearby people and communicated with them. They sent messages in simple ways. Early signals for communication included smoke from fires and the sounds of drums.
Then people formed towns, and then cities, as safe places to live. Soon they began to develop other ways to communicate, to spread information. People began to buy and sell things to one another. Because of their business, they developed writing systems to keep records and to send messages. Life was changing for many people. Business caused changes, and so did the invention of the printing press. Many more people learned to read then.
Suddenly communication and knowledge improved greatly. People sent letters and news by horse and carriage. Later the mail went by train and then by airplane. World communication was now a possibility.