When you use a computer or a phone, sometimes different parts need to talk to each other to get things done. When they talk to each other, they use something called an "interface".
Think of it like when you need to talk to your friend. You both have to speak the same language and understand each other’s words. The interface is like the language that the computer parts speak to each other.
Sometimes people want to make new parts for computers and phones that can talk to existing parts. But they need to know exactly how to talk to the existing parts so they work together.
To help with this, people can create something called an "open service interface definition". This definition is like a set of instructions that explain how new parts can speak the same language as the existing parts.
It’s like if you wanted to play a game with your friend, but you didn’t have the rules. You could ask your friend for the rules, and they could explain them to you. The open service interface definition is like the rules for how different parts of a computer or phone can talk to each other.
So, when people create a new part like an app or a plugin for a computer program, they can use the open service interface definition to make sure it can talk to the other parts of the program. This helps everything work better together and make the computer or phone work the way it’s supposed to!