The stock of a corporation is a summation of all the shares of its stake holders

the stock of a corporation is partitioned into shares which is simply defined as a unit of capital of a company
allocated to an individual .
There are different types of shares, each having distinctive ownership rules privileges ,or share.

A legal document is always issued to shareholders of a every corp,this document is known as stock certificate

Stocks can also be referred to as a different financial instrument such as government bond or loans common to all kinds of  marketable securities

TYPES SHARES OF STOCK 
common  and preferred  shares of stock