A tape library is like a really big toy box with lots of shelves for storing toys. But instead of toys, it stores something called data. Data are like stories that your parents read to you, but instead of words on a page, they are a bunch of numbers that computers use to do stuff.
The tape library has a robot helper that can take out tapes with data on them and put them in a computer so the computer can read or write (add more data) to it. The robot helper uses a barcode scanner to find the right tape and takes it out of its shelf with a special arm.
Just like you have to put your toys neatly back in the toy box after you're done playing, the robot helper has to put the tapes back in their correct spots when they're not needed anymore. This is to keep everything organized so that the computer can find what it's looking for quickly and easily.
The tape library can hold a lot of tapes, even more than you have toys! This is useful for businesses and organizations that have a lot of data they need to store and keep safe. It's like having a really big and organized closet for all their important information.