Overview#Packet switching is a method of grouping data which is transmitted over a digital network into packets which are made of a header and a payload.
In the early 1960s, American computer scientist Paul Baran developed the concept Distributed Adaptive Message Block Switching with the goal to provide a fault-tolerant, efficient routing method for telecommunication messages as part of a research program at the RAND Corporation, funded by the United States Department of Defense
The new concept found little resonance among network implementers until the independent work of United Kingdom computer scientist Donald Davies at the National Physical Laboratory (United Kingdom) in 1965. Davies is credited with coining the modern term Packet switching and inspiring numerous packet switching networks in the decade following, including the incorporation of the concept in the early ARPANET in the United States.
Packet switching was later used for the NPL Data Communications Network was a local area computer network operated by a team from the National Physical Laboratory. Following a pilot experiment during 1967, elements of the first version of the network, Mark I, became operational during 1969 then fully operational in 1970, and the Mark II version operated from 1973 until 1986.