What is the "vesting period" of an ESOP?

The period between the grant date and the vesting date

The "vesting period" in an Employees Stock Option Plan (ESOP) refers to the duration of time between the date when stock options are granted to employees (grant date) and the date on which the employees become entitled to exercise those options (vesting date). During this vesting period, employees must meet specific conditions, such as staying employed with the company for a certain length of time, in order to gain the right to exercise their stock options and purchase shares at the predetermined exercise price.