1, 2, 3, Chakra Systems
To be able to break down the full understanding of chakras in a few basic paragraphs would be an utterly impossible task to do.
Being there are so many variables as to how one looks and percieves the entire functioning along with eaches own beliefs to the matter.
Variables go as far as to religious/spiritual beliefs, energy theory, Eastern model formation, Western model formation, new/old belief system, old sandscripts vs new sandscripts, different chakra number models, sound/vibration, elements and even meridians.
This can help provide a quick overall view to give one an overstanding of the most common chakra number model.
The newly common number model and well known in the Western (meaning Euro-American culture and also a certain percentage of modern Indian culture that obtain their information from the Euro-American cultural matrix.) is the 7 chakra model system.