How does "import" function works?

Hello, I did some puzzles where you use the function “import”, but I don’t understand how can I apply it when I code freely, like in the playground.
How does it works?

Import are from another function containing the data such as the arrays used for many of the lessons. It might even be from a completely different code created a while back and used for the similar purpose of the library in grasshopper that contains the custom functions like dropBox (). You’re importing the data contained in a location outside of the current code being written. Allowing you to use it in a new code from importing it instead of rewriting it every time you want to use it in a new code you’re working on. Some of these are built in the app such as pickRandom(). Which is a function created for the app that you can use outside of grasshopper but only after creating the function that can be imported for use in coding outside of grasshopper