For most children, the actual process of learning begins much
before school. Many children already know their alphabets, the
names of animals, colors and other more complicated stuff before
they reach school. This is mostly due to the hard work of a member
of the family who has taken the time to teach the child.
Homeschooling is just a natural progression from here. Instead of
sending their children to a public school, parents make their own
curriculum and teach their children in ways that best suit the
child. This is homeschooling, in its most simplistic form.