Please allow me to shatter your expectations here.....and not in nice way..an object lesson if you like which you may care to learn from.
Advice, help and support are freely offered by many on here to valid queries....however...in your case it would appear that, like many of your generation, you lack the ability and discipline to actively research the question topic and present your findings based on...and here comes the crucial bit....your own work and efforts
I say the above because it appears that you are too lazy to actually do the basic research, so have decided to post a query on here in the hope that others, will in effect, do the work for you....and you can thus present it to the teacher / tutor with glowing pride.
This is not a personal dig by the way...you are but one representative of many who simply lack the discipline required....and cannot or will not understand that this concept is a basic requirement to study...as you have been spoon fed by an education system now dedicated to meeting targets and convincing pupils they are educated and have a right to pass exams...irrespective of whether they know the subject or not.