All the terms are very similar, with minor differences in meaning:
Job seeker: A person actively seeking employment or who has successfully gone through the selection process and started working for an employer.
Candidate: A person applying for a specific position or job but has not yet been hired. Candidates undergo the selection process to secure a job.
Worker: A person who performs work or provides services, regardless of employment status, including employees, self-employed individuals, freelancers, and temporary workers.
Official: A person who performs administrative or office duties, often in the public sector or in institutions. Employee: A person who works under an employment contract, providing their services to an employer in exchange for a salary. This term encompasses all the categories mentioned above.