ARPANET is considered as the precursor of the Internet. One might think of the bulletin board systems or the packet radio services as precursors of the Internet. But the Internet is the direct successor of the Advanced Research Project Agency Network, abbreviated as ARPANET.
The idea of the modern-day Internet can be traced back to a networking project at the Information Processing Technology Office (IPTO) established by ARPA. Lawrence Roberts, a doctor of chemistry and a degree-holder in electrical engineering was appointed as the head of this project of implementing a network.
Lawrence Roberts based the implementation on the work of Paul Baran, who had proclaimed packet switching as being an effective technology for the design of robust networks. His efforts bore fruit when a packet switching could be employed to connect network nodes for the first time ever in 1969. Yes, this was how ARPANET was born.
The commercial use of networking began in 1988. After the creation of the World Wide Web by Tim Berners-Lee, the Internet became immensely popular. Today, it has grown into the world's largest information base and an excellent communication platform. The phenomenal growth of the Internet finds its roots in ARPANET that was developed decades ago.