A master service agreement (MSA) is like a big promise between two people, companies or groups. It's like saying "hey, we agree to work together and help each other out for a long time."
It's a document that lists all the important things about the work that will be done together. Like when it will start and end, what type of work will be done, how much money will be paid, and lots of other details.
Imagine you have a friend who loves to play games with you. But, every time you want to play a new game, you have to keep explaining the rules to your friend. It can get tiring! So, you both decide to write down all the rules for every game you like to play in a special notebook that you call 'Game Book.' You both sign it and agree to follow it every time you play together. This way, you can just open the Game Book and start playing without any issues.
The master service agreement is a bit like this 'Game Book.' It helps you avoid having to explain everything over and over again each time you work with someone new. It makes things easier and more efficient!