When creating a Share Purchase Agreement, it is important to include details about the shares being sold, such as the type of shares. Common, preferred, voting, and non-voting are all terms that can be used to describe shares.
The class of shares, common or preferred, can impact the shareholder's portion of company profits or the amount they receive in the event that the company is liquidated, and whether a shareholder has voting or non-voting shares determines whether the shareholder is or is not eligible to vote at shareholders' meetings.
A common share is a type of share that is held most frequently by shareholders. A preferred share is generally a more valuable type of share that can mean different things to a company depending on what was agreed upon during the company's incorporation. Oftentimes, preferred shares are non-voting. In addition, shareholders with preferred shares will typically receive priority for profits (or liquidation, if it occurs) as compared to common shareholders.
Keep in mind, most corporations will have common shares, but not all will have preferred shares.
Companies that offer multiple types of shares will also sometimes have a series (Class A, Class B, Class C, etc.), which can be worth different monetary amounts. For instance, 100 Class A Common Voting Shares may not be worth the same value as 100 Class B Common Voting Shares.
A company's share structure can often be found in the company's Articles of Incorporation.