Step 1: Think of it like folders on a computer.
Just as a folder on a computer groups related files together so they stay organized and easy to find, Java needs a similar mechanism to group related classes and interfaces.
Step 2: Name that grouping mechanism.
This mechanism is called a package, and it works as a namespace that helps avoid naming conflicts between classes written by different programmers while also giving some control over access.
Step 3: Confirm it with a familiar example.
The commonly used java.util package, for instance, bundles together many utility classes such as ArrayList and HashMap, which is a direct illustration of a package being a collection of classes and interfaces.
\[ \boxed{\text{Package}} \]