A service data object is like a special messenger that helps different parts of a program talk to each other. Imagine you have a big toy castle, and you have many toy knights that each have a different job, but they all need to work together to keep the castle safe.
The service data object is like the toy king who gives each knight a special message or task to do. Each knight knows what it needs to do and can work together with the other knights to get the job done.
In a computer program, a service data object helps different parts of the program communicate and share information with each other. It can help make sure that data is organized and accessible to everyone who needs it, just like the toy king makes sure each knight has the right job to do.