When the internet emerged browsers used for displaying and rendering HTML pages with limited JavaScript or VBScript scripts. Today time changed and browsers act like an operating system or container that provides a lot of functionality built-in or with plugins. Internet users use plugins for different functions like post twitter, bookmark, save the password, remotely manage applications, etc. The plugin provides flexibility for the users but also provides security weaknesses.
List Plugins
Existing builtin of user-installed plugins can be viewed with the following URL which should be entered to the address bar.
Extensions or Plugins
chrome://extensions/

We can see that Google Mail Checker
, LastPass Password Manager
plugins are installed into the chrome.
Built-in Plugins
Google Chrome also provides some built-in plugin in order to provide general functionality to the users. Adobe Flash Player
, Chrome PDF Viewer are some of them. We can list these built-in plugins with the following command or URL from the address bar.
chrome://plugins/

As we can see that there are only builtin plugins installed currently in the screenshot.
Install Plugins
Plugins can be installed in different ways and from different sources for Chrome browser but the official and most secure one is installing from Chrome Web Store which can be navigated with the following URL.
https://chrome.google.com/webstore/category/extensions

For example, we want to install the plugin named google mail checker. We can search it with the search box located left upper corner . In the left sidebar, we can filter plugins according to their ratings from 2 stars to 5 stars. Another menu is Features menu where we can filter plugins according to the following categories
- Runs Offline
- By Google
- Free
- Available for Android
- Word with Google Drive
After we search we get the following screen. We just click the Add To Chrome Button to the related plugin in the list.

In the next popup box click Add extension.

After installation is completed we generally get a popup like below and the icon of the plugin is added to the chrome bar.

Activate Plugins
Plugins can be activated or dis-activated from the extension list page just click checkbox Enabled for this operation.

Remove Plugins
Plugins can be removed from Chrome by click the trash cab icon in the plugin list.

Allow In Private or Incognito Mode
Private or Incognito Mode is used to browse the internet privately with privacy. Private or Incognito mode will do not store any information to the disk. By default, plugins are not enabled in Private or Incognito mode. If we want to use them we can enable them by clicking Allow in incognito
checkbox.