A Chair of Governors has a casting vote where an equal number of votes is cast for and against a motion. She/he may then, and only then, cast a second vote to decide the issue (or vote for the first time if he/she abstained on the first vote).
When there is an equal number of votes in favour of and aginst a proposal, the voting procedures may lay down that somebody has a casting vote to end the deadlock. The chairman of a companyâ€™s board of directors, for example, frequently has a casting vote. In effect a person with a casting vote votes twice on issues where the votes are equally divided.
A casting vote is a vote given to the presiding officer of a council or legislative body in order to resolve a deadlock and which can be exercised only when such a deadlock exists. Examples of officers who hold casting votes are the Speaker of the British House of Commons and the Vice President of the United States (in his constitutional capacity as President of the Senate).