With regard to workers’ rights, there is a difference between rights that workers have as a matter of law and rights that they have because of the contracts that they have signed. In general, the second kind of rights can only be added to the first. That is, a contract cannot take away rights that workers are given by law.
In the United States and most other countries, governments pass laws giving certain rights and protections to workers. For example, workers have the right not to be discriminated against on the basis of their race, their sex, or other characteristics. They also typically have rights to things like scheduled breaks and safe working conditions. These are statutory rights because the rights are given by law.
Some workers, however, work on the basis of contracts that they have signed. These contracts spell out workers’ rights. These are contractual rights. What is important to note is that contractual rights cannot detract from statutory rights. That is, a firm cannot have employees sign contracts in which they give up rights that they have been given by law.