This is the answers of group seneca8: Group8 members: Jeff, bsdpeng, ali, slao, evanw
* What is a Firefox Extension? The main purpose of Firefox Extension is to add some new features to Firefox; those features vary from a simple toolbar button to a totally new functionality. By offering such extensions, it is more flexible when it comes to customize Firefox to meet users' own requirements and preferences and at the same time, useful to keep Firefox itself clean and light. Some of the popular Firefox Extensions examples are Deutsches Wörterbuch, Download Statusbar, Dictionnaire MySpell, Adblock Plus, and Forecastfox.
* 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. For example, I found an add-on named "Download Statusbar": https://addons.mozilla.org/firefox/26/ I want to install, just click the button "Install Now". After installation, I should restart Firefox.
* List and describe as many extensions/themes as you can -Chatzilla: An IRC chat client for a community to discuss any issues. -DOM Inspector: Inspect the DOM of HTML, XUL, and XML pages, including the mail chrome. -Adblock: Gives the user to remove unwanted web page ads in the future browsing. -Download Statusbar: replaces the popup download window with a status bar notification. -Blocksite: Block any site of your choice. -DownloadHelper: Allows you to download content such as music and video from a webpage.