As investors we are not able to deal with the equity market directly.
It would be like entering and trying to find our way through an
unending maze. The markets on their part, are too large, to attend to
every single investor directly. This would be a Herculean task and a
management nightmare for it. So, the markets introduce and authorize
the middleman to act on its behalf. This middleman is also called the
"Broker".
For a better understanding, visit: http://www.narachinvestment.com/broker.htm