At the time of birth, a baby as about one hundred billion neurons which is twice the number of the neurons that is present in an adult, but a proper network and connections are not yet established, with a relatively low number of synapses present. As the child grows up and enters a learning phase, new synapses start forming and the number increases drastically in the first few years following the child's birth. Over time a lot of the connections are eliminated if they are hardly ever used, as a part of the child's brain development and this is a natural process.
