Shakti (Force)

The female cosmic power, mostly in connection with Shiva, personified as Goddess Parvati.

The masculine is static, the feminine is the driving force. This idea is compared by the wheel. The hub is static, the wheel turns around it. Shiva is the powerful, Shakti is the power.

Read about Shakti here
http://utkarshspeak.blogspot.com/2010/10/cult-of-shakti.html
http://utkarshspeak.blogspot.com/2010/10/myth-of-sati.html