The Contracts of Employment Act is a set of rules that people and companies have to follow when they hire someone to work for them. It was made in 1963, which is a really long time ago!
The act says that when someone gets a job, they have to get a written contract that explains things like what they will be doing, how much money they will make, and how many hours they will work. This is like a special agreement that the person who is hiring them (called the employer) and the person who is going to work for them (called the employee) both sign.
The act also says that if the employer wants to make any changes to the contract, they have to talk to the employee first and get their agreement. This is like a grown-up version of asking your friends if they're okay with playing a different game instead of the one you'd planned.
The Act helps make sure that both the employer and the employee know what to expect and that everyone is treated fairly. So, it's kind of like a rulebook for how grown-ups have to behave when they're hiring someone to work for them.