What is the triple bottom line? What does it measure?

The triple bottom line consists of three Ps: profit, people and planet. It aims to measure the financial, social and environmental performance of the corporation over a period of time.
The triple bottom line suggests that firms should be focusing on three interdependent measures of success.
One is the traditional measure of corporate profit; the second is a measure of a firm's employees and a firm's responsibility throughout the organization. The third pertains to how environmentally responsible a firm has been.