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What is a plugin?
A plugin is a small add-on that gives an app new features without changing the app itself.
- Category Agents & tools
- Also called plug-in, add-on
- Updated 20 Oct 2026
Plugin, explained simply
A plugin, also called an add-on, is a small piece of software that plugs into a bigger app. It adds a new feature.
It matters because you can customize your tools. You install only what you need and remove it later.
For example, a browser extension that blocks ads is a plugin. An AI coding tool can also take plugins that add new commands.
Only install plugins from sources you trust. A plugin often gets access to what the app can see.
On ITG Now, our free tool guides say when a tool has plugins and how to add one step by step.
Related terms
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Questions people ask about Plugin
Are plugins free?
Many are free. Some cost money, so check the page before you install.
Plugin vs extension: what is the difference?
They are nearly the same idea. Different apps just use different names for add-ons.
Is it safe to install a plugin?
Stick to trusted sources and read what permissions it asks for. Remove ones you no longer use.