Ruby Academy · Lesson

What Are Gems?

Learn about RubyGems, the package management system for Ruby.

Lesson 1 of 410 steps

What Are Gems? is a free Ruby Academy lesson on CoddyKit. This is lesson 1 of 4. Any 3 lessons of this learning path are free to read in full — after that, CoddyKit PRO unlocks every lesson, plus hands-on practice with a built-in code editor and a 24/7 AI tutor. It is part of the Ruby Academy learning path, and your progress syncs across the web and the CoddyKit app. The Ruby Academy course includes 4 lessons in total.

Introduction to Ruby Gems

What Are Gems?

Gems are reusable libraries that add functionality to Ruby applications.

RubyGems is the package management system for installing and managing gems.

What Are Gems? — illustration 1

What is RubyGems?

RubyGems is the standard package manager for Ruby.

It helps install, update, and manage Ruby gems efficiently.

Checking Installed RubyGems Version

Use the following command to check your installed RubyGems version.

gem -v

Listing Installed Gems

Use the gem list command to see installed gems.

gem list

Updating a Gem

To update a gem to the latest version, use:

gem update gem_name

Viewing Gem Details

Use the following command to see more details about an installed gem:

gem info gem_name

Checking RubyGems Sources

View the gem repositories your system is using with:

gem sources

Alternatives to RubyGems

Other tools for managing Ruby dependencies include:

  • Bundler: Manages gem dependencies for projects.
  • RVM (Ruby Version Manager): Handles Ruby versions and gemsets.
  • rbenv: Manages multiple Ruby versions.

Congratulations!

You have learned what Ruby gems are and how they are managed with RubyGems.

Next, you will learn how to install and use gems in your projects.

What Are Gems? — illustration 10
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Frequently Asked Questions

Is the “What Are Gems?” lesson free?

Yes — any 3 lessons of the Ruby Academy learning path, including “What Are Gems?”, are free to read in full here on the web. After that, CoddyKit PRO unlocks every lesson, plus interactive practice with a built-in code editor and a 24/7 AI tutor. The Ruby Academy course includes 4 lessons in total.

What will I learn in “What Are Gems?”?

Learn about RubyGems, the package management system for Ruby. You practise Ruby Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start Ruby Academy?

No prior experience is required. Ruby Academy on CoddyKit is structured for beginners through advanced learners, so you can start here or from the beginning and move at your own pace. This is lesson 1 of 4.

How long does the “What Are Gems?” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this Ruby Academy lesson?

Yes. Every Ruby Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

All lessons in this course

  1. What Are Gems?
  2. Installing and Using Gems
  3. Managing Dependencies with Bundler
  4. Creating Your Own Gem
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