A part-time contract is like an agreement between a person who wants to work for a company but only for a certain amount of time. This means that they will not work the full time that a regular worker does. This is usually because they have other things they need to do like take care of their family or go to school.
When you sign a part-time contract, you and the company agree to how many hours you will work each day or each week. This means that you will only have to work for a certain amount of time and then you can do other things.
It's like when you have a friend come over to play, but they can only stay for a little while because they have to go do something else. You can still have fun and play together, but you know that they can't stay for too long. It's the same thing with a part-time contract.
So, a part-time contract is a way to work for a company, but with less hours than a full-time worker, allowing you to have time for other important things in your life.