Okay, let's imagine that you are playing with your toys and your mom tells you to put away your blue car, your red ball, and your green dinosaur. You have to remember which toys your mom told you to put away, right? That's kind of like session-based testing.
Session-based testing is when people try out different parts of a computer program or website and write down what they do and what happens. Just like you had to remember which toys to put away, testers have to remember what they did in the program so they can write it down later.
Testers use different "sessions" to test the program. A session is like a time period when they are testing. They might use one session to focus on making sure the program does what it's supposed to do. Another session might be used to see what happens when someone tries to use the program in a way it's not supposed to be used.
When the testers are done with all their sessions, they write a report that tells the developers if they found any problems or if everything worked okay. It's like they're telling your mom if they put away the right toys or not.
So, session-based testing is basically when people test a program or website, write down what they did, and report back to the people who made the program. It's important to make sure the program works the way it's supposed to so that everyone can use it easily and without any problems.