All meetings of a corporation may be divided into meetings of shareholders and of directors.
There are four usual types of shareholder meetings:
(1) Annual Meetings of Shareholders. At the annual meeting, the annual report is presented and explained by management and the 'old' board, and then the shareholders elect the 'new' board. Other business may be conducted in accordance with the "Notice of Meeting".
(2) Regular Meetings of Shareholders. Some corporate bylaws require that there be "regular" (usually quarterly) meetings of shareholders, at which quarterly financials are presented and other business conducted.
(3) Special Meetings of Shareholders. (Also called "Extraordinary Meetings"). These meetings may be called by the board or by management, in accordance with the bylaws, to consider emergency and other special matters, as set forth in the "Notice of Meeting".
(4) Regular and Special Meetings of Shareholder Classes. For corporations with separate classes of stock outstanding, meetings of such shareholders are held to exercise the rights of the class.
Similarly, there are three usual types of meetings of the board of directors.
(1) Annual Meetings of the Board of Directors. At the annual meeting (which usually occurs just after the annual meeting of shareholders), the 'new' board elects a chairperson, vice chair, etc., and then consider other business, such as election of officers, the creation of special sub-boards and committees (the executive board, compensation committee, etc.), and the like.
(2) Regular Meetings of the Board of Directors. Regular meetings are held in accordance with the bylaws and may be scheduled as often as monthly but are usually scheduled quarterly.
(3) Special Meetings of the Board of Directors. As with the special (or extraordinary) meetings of shareholders, these meetings are held to address unusual or emergency situations.
Again, all such meetings are described in detail in the bylaws of the corporation. The bylaws of publicly held corporations are available from the corporate secretary and are often available online.
Hope this helps.