A probation period is sometimes use for new employees. It is a duration at the beginning of employment during which either the employee or employer can terminate the employment at a reduced notice period.
A probation period's purpose is to determine if the new employee is a good fit for the organisation and have the requires skillset to perform their duties.
A probation period is typically between 1 and 3 months depending on the nature of the role. A probation period might be longer for roles which take longer to assess.
At the end of the probation period, the employer or line manager of the employee will inform them if they have passed the probationary period or not.