A more thorough explanation:

Job security refers to the protection of an employee's job, often through a union contract. It means that an employee can feel confident that they will not lose their job without a valid reason.

For example, if an employee is part of a union, their contract may include provisions that protect them from being fired without just cause. This means that the employer must have a valid reason for terminating the employee, such as poor performance or misconduct.

Another example of job security is tenure in academia. Professors who have achieved tenure have a high level of job security, as they cannot be fired without just cause and due process.

Overall, job security is important for employees because it provides stability and peace of mind. It allows them to focus on their work and contribute to their organization without fear of losing their job.