6.(a)What is the nature of a share? (s1070A)

(b)What is the contractual analysis the purchase of a share?

8.Broadly, what rights does a person acquire when they become a shareholder in a company? Whymay a company wish to have different classes of shares?

I need answers for those two questions. The subject its Corporations Law. however, the answers can be briefly not in depth and details like maybe 5 lines each is enough but relate some law cases or sections. thanks :)