What is a Substation ?

In India Power plants generates power at voltage 11 KV . Since, this voltage do not suffice to cover the large distance from power plant to our homes. To do this voltage raised from 11 KV to 220 KV / 400 KV and then these voltages should bring to 440 V or 230 V to use in our homes or industries. To do this we use Substations. In substations their is a Transformer which transmits the power from one voltage to another voltage. The is also some protecting devices like Breakers, Lightening Arresters which protect those lines from faults.