Casual employees refer to workers who are hired on a temporary or short-term basis, without any guarantee of long-term employment. They usually work for an organization on an as-needed basis and may be called upon to fill in gaps in the workforce due to vacations, illnesses, or other absences. Casual employees are not typically offered benefits such as health insurance, pensions, or paid leave, and their hours of work can vary greatly depending on the needs of the organization.