Google Apps Script is a scripting language developed by Google to extend the functionality of its various services such as Google Sheets, Google Docs, and Gmail. With Google Apps Script, you can automate tasks, add custom functions, and create new applications within Google Workspace. This beginner's guide will introduce you to the basics of Google Apps Script, show you how to write it with an example, and explore its best applications.

Getting Started with Google Apps Script
Google Apps Script is a high-level scripting language based on JavaScript. It is easy to learn and has a lot of powerful features that make it ideal for creating custom scripts to automate workflows and extend the capabilities of Google Workspace. You can write Google Apps Script in the Script Editor, which is built into Google Sheets, Docs, and other Google Workspace apps.

To create a new script, open the Script Editor by going to Tools > Script Editor in the menu bar of any Google Workspace app. You will see a blank script with a few lines of code already added. The default function is the function that gets run when the script is executed. You can create custom functions to extend the functionality of Google Workspace by adding them to the script.

Writing Google Apps Script with an Example
One of the best ways to learn Google Apps Script is to start with a simple example. Let's create a function that will convert a given temperature from Celsius to Fahrenheit. Here is the code:

```
function celsiusToFahrenheit(celsius) {
  var fahrenheit = (celsius * 9/5) + 32;
  return fahrenheit;
}
```

This script creates a custom function named `celsiusToFahrenheit` that takes a temperature in Celsius as an input parameter and returns the temperature converted to Fahrenheit. To use this function, save the script and then go back to the Google Sheets document. In any cell, type `=celsiusToFahrenheit(25)` and press Enter. The cell will display the converted temperature of 77°F.

Best Applications of Google Apps Script
Google Apps Script can be used in many ways to automate workflows, create custom applications, and extend the functionality of Google Workspace. Here are a few examples of its best applications:

1. Automating data entry and manipulation in Google Sheets
2. Creating custom email templates and automating email responses
3. Integrating with third-party APIs to extend the functionality of Google Workspace
4. Building custom applications that run on Google Workspace
5. Creating add-ons and extensions for Google Workspace

Conclusion
Google Apps Script is a powerful tool for automating workflows, creating custom applications, and extending the functionality of Google Workspace. This beginner's guide has introduced you to the basics of Google Apps Script, shown you how to write it with an example, and explored its best applications. With some practice, you can create custom scripts to automate workflows and add new features to Google Workspace.