They can only state whether you worked there and what dates.
Legally your previous employer cannot give a negative feedback to a potential new employer. All they can do is verify employment, dates of employment, and the position held by the employee.
Employ is a verb. Employer and employee are nouns.
When the employees believes that the reference provided by the employer was not true and resulted in defamation of the employee
When the employees believes that the reference provided by the employer was not true and resulted in defamation of the employee
Legally? There are none for the employer. Employee status is not secret or confidential - expect no privacy.
to protect both the employee and employer
An employment contract dictates the conditions of employment, such as salary, vacation, benefits, etc. An "at will" employee serves at the pleasure of the employer, meaning their employment can be terminated at any time, for any reason, or for no reason at all. The effect of an employment contract on an at-will employee would be to set salary, benefits and so on as long as the employee worked at that employer.
Employment legislation is usually created to protect the employee from abuses of the employer.
A contract of employment is a document which describes the employer and employee agreement. The document contains the duties to be done over a certain duration and the amount of remuneration to be expected.
to protect both the employee and employer
An employer has a duty to inform the employee of an changes to the employment terms. If an employer is out on workers' compensation, and they are terminated, the employer has a duty to communicate that information to the employee and pay that employee any money they have due to them.
As little or as much as the employer wants, as long as there are no falsehoods.