Outstanding shares refers to the number of shares of a corporation that have been issued and remain outstanding at a given time. This number cannot be greater than the number of authorized shares. Practices vary, but for US companies we typically issue between 5 and 10 million shares to the founders of a company at incorporation.
The term “issued shares” is sometimes used interchangeably with “outstanding shares,”
but is less precise because it can be read to include shares that had previously been
issued but are no longer outstanding – for example, shares that a corporation issued and
then later bought back.