This is the answers of group seneca8:
* What is a Firefox Extension?
* What is a Firefox Theme? A theme is a customization of the look and feel of the browser. For example, a theme can change the default colours and the icons used for the buttons.
* How to get and install Firefox add-ons. We can get Firefox add-ons from the website: https://addons.mozilla.org/ Search and choose you want. * List and describe as many extensions/themes as you can