Definition of a Probation Period
A probation period is defined as a temporary employment phase where a person is employed against a clear-cut permanent position in the organization after undergoing the hiring procedure. Usually, this period lasts six months, during which the employee must render services to the satisfaction of the employer.
Now, the clause "to the satisfaction of the employer" is very difficult to interpret. It is often unclear what will satisfy the employer, and mostly, the employee is not promoted to a permanent position if the company does not want them. This can happen by giving a week's notice or a month, as the case may be, even without providing any valid reason for the decision.