The president, secretary and treasurer are offices required by the Illinois Condominium Property Act and the Illinois Common Interest Community Association Act. The governing documents for some associations also provide for the office of vice president, or such other officers as the board may appoint.
The president presides over the meetings of the board and of the unit owners and creates the agenda for board meetings. The president carries out the decisions of the board and executes amendments to the governing instruments on behalf of the board. Coming as a surprise to many, note that the president does not inherently have greater authority or decision-making power than any other board member. Nonetheless, many boards "delegate" day-to-day decision making to the president. Most do this informally based on a misunderstanding of the president's customary role; however, the appropriate way to accomplish this would be by way of a board resolution adopted at a board meeting.
The vice president, in the absence of the president, or the inability or refusal of the president to act, performs the duties of the president. When so acting, the vice president has all the powers of and is subject to all the restrictions imposed upon the president. The vice president also performs such other duties as from time to time may be assigned to him by the president or by the directors.
The secretary is the keeper of the books and records of the association, and the keeper of the minutes of all meetings of the board and of the unit owners. Note that the secretary need not necessarily be the person who physically takes the minutes (although this is a common duty of the secretary), and the board may appoint a "recording secretary" for this purpose. The secretary certifies meeting minutes and resolutions of the board/unit owners as being true and correct. Often, the secretary is the officer who mails and receives all notices on behalf of the association.
The treasurer keeps the financial records and books of account of the association. Depending on the governing documents, the treasurer may have charge and custody of and is responsible for all funds and securities of the association, receives and gives receipts for moneys due and payable to the association from any source whatsoever, and deposits all such moneys in the name of the association in such banks, trust companies or other depositories as provided in the governing documents.
If the bylaws so provide, any two or more offices may be held by the same person. Otherwise, each office needs to be held by a different person. All officers, as between themselves, have the express authority and perform such duties in the management of the property and affairs of the association as may be provided in the governing documents (declaration/bylaws), or as may be determined by resolution of the board not inconsistent with the governing documents. However, there may be certain duties and implied authority recognized by the common law from time to time.