How to fix 'package does not exist' error in Java

# Introduction

As a Java developer, you will likely encounter the "package does not exist" error during your programming journey. This error occurs when the Java compiler cannot locate a package that your code is trying to use. This lab will guide you through understanding Java packages, creating a project that demonstrates the error, and then resolving the issue properly.

**Important for Beginners:** When copying Java code in this tutorial, pay careful attention to the syntax. Java is case-sensitive and requires exact syntax. Common mistakes include:

- Adding extra keywords like `public` before `package` declarations
- Incorrect spacing or punctuation
- Missing semicolons or braces

By the end of this tutorial, you will understand how to fix and prevent this common error in your Java applications.