The initial period of work when someone starts a new job or a period where someone has underperformed and is given a period of time to show improvement or face some consequences such as termination. The length of a probationary period can vary from a month to several years according to Wikipedia though 3 months is common.
In a workplace setting, probation is a status given to new employees of a company or business. It is widely termed as Probation Period of an employee. This status allows a supervisor or other company manager to closely evaluate the progress and skills of the newly hired worker, determine appropriate assignments and monitor other aspects of the employee – such as how they interact with co-workers, supervisors or customers.
A probationary period varies widely depending on the business, but can last anywhere from 30 days to several years. If the new employee shows promise and does well during the probationary time, they are usually removed from probationary status, and may be given a raise or promotion as well (in addition to other privileges, as defined by the business). Probation is usually defined in a company's employee handbook, which is given to workers when they first begin a job.
The probationary period also allows an employer to terminate an employee who is determined not to be doing well at their job or otherwise deemed not suitable for a particular position. Whether or not this empowers employers to abuse their employees by, without warning, terminating their contract before the probation period has ended; is open for debate.