Q: How does the Raspberry Pi store its files? When I do sudo apt-get purge firefox it asks me to save it and quit or run as a different user. When I select quit, it says Are you sure? [y/N] I don't see any files to be saved there. So where does it store firefox in RAM? I don't see any folder named firefox, chrome etc. I tried cd /usr/bin/firefox/ to view its source code, but cd /usr/bin/firefox/firefox-bin gives bash: cd: /usr/bin/firefox/firefox-bin: Not a directory Please someone clarify the situation? A: The default Ubuntu (and Debian) system-wide installation of Firefox will be in /usr/lib/firefox, whereas your own personal install will be at ~/.mozilla/firefox/blah.default. Most users keep there personal install of Firefox in their home directory, so that it would not impact other Firefox users (if there were Firefox users) on the system. Regarding your comment I think I have to kill firefox? (killall firefox) It depends, if the process is currently running it would need to be killed. You can kill any process by process name, or ID, by using pkill firefox pkill firefox killall firefox killall firefox The last example would only work if it was running on a shell that supports aliases. Example: If you have the firefox browser installed and running then ps -aux | grep -i firefox will show the PID of the firefox process. In the example above I used ps -aux for the first column and grep -i firefox for the second. Thus the last command would kill the firefox process based on its PID, if you were not sure which PID to kill, you could use ps -aux | grep -i firefox | awk '{print $2}' | head -n 1 or ps -aux | grep -i firefox | cut -d ' ' -f2 for example. The default ubuntu system-wide firefox installation To locate the firefox executable you can use the locate command locate firefox which shows /usr/lib/firefox-trunk /usr/lib/firefox /usr/lib/firefox-addons/plugins /usr/lib/firefox-addons/webconsole /usr/lib/firefox-addons/distribution /usr/lib/firefox-addons/distribution/distribution.ini /usr/lib/firefox-addons/distribution/distribution1.ini /usr/lib/firefox-addons/distribution/distribution2.ini /usr/lib/firefox-addons/distribution/distribution.properties /usr/lib/firefox-addons/distribution/distribution1.properties /usr/lib/firefox-addons/distribution/distribution2.properties /usr/lib/firefox-addons/distribution/distribution_version /usr/lib/firefox-addons/distribution/distribution1.version /usr/lib/firefox-addons/distribution/distribution2.version /usr/lib/firefox-addons/distribution/distribution_time /usr/lib/firefox-addons/distribution/distribution1.time /usr/lib/firefox-addons/distribution/distribution2.time /usr/lib/firefox-addons/distribution/distribution.jar /usr/lib/firefox-addons/distribution/distribution1.jar /usr/lib/firefox-addons/distribution/distribution2.jar /usr/lib/firefox-addons/distribution/install.rdf /usr/lib/firefox-addons/distribution/distribution.rdf /usr/lib/firefox-addons/distribution/firefox.png /usr/lib/firefox-addons/distribution/firefox_24.png /usr/lib/firefox-addons/distribution/firefox_small.png /usr/lib/firefox-addons/distribution/install.properties /usr/lib/firefox-addons/distribution/locale.en-US.properties /usr/lib/firefox-addons/distribution/locale.en-US.qm /usr/lib/firefox-addons/distribution/locale.es-ES.properties /usr/lib/firefox-addons/distribution/locale.es-ES.qm /usr/lib/firefox-addons/distribution/locale.fr.properties /usr/lib/firefox-addons/distribution/locale.fr.qm /usr/lib/firefox-addons/distribution/locale.it.properties /usr/lib/firefox-addons/distribution/locale.it.qm /usr/lib/firefox-addons/distribution/locale.ja-JP.properties /usr/lib/firefox-addons/distribution/locale.ja-JP.qm /usr/lib/firefox-addons/distribution/locale.pl.properties /usr/lib/firefox-addons/distribution/locale.pl.qm /usr/lib/firefox-addons/distribution/locale.pt-BR.properties /usr/lib/firefox-addons/distribution/locale.pt-BR.qm /usr/lib/firefox-addons/distribution/locale.ru.properties /usr/lib/firefox-addons/distribution/locale.ru.qm /usr/lib/firefox-addons/distribution/locale.zh-CN.properties /usr/lib/firefox-addons/distribution/locale.zh-CN.qm /usr/lib/firefox-addons/distribution/package.properties /usr/lib/firefox-addons/distribution/patch-environment.jar /usr/lib/firefox-addons/distribution/patch-firefox.jar /usr/lib/firefox-addons/distribution/rdf.localized /usr/lib/firefox-addons/distribution/skin1.jar /usr/lib/firefox-addons/distribution/skin.jar /usr/lib/firefox-addons/extension /usr/lib/firefox-addons/extension/chrome /usr/lib/firefox-addons/extension/icons /usr/lib/firefox-addons/extension/icons/16.png /usr/lib/firefox-addons/extension/icons/32.png /usr/lib/firefox-addons/extension/icons/48.png /usr/lib/firefox-addons/extension/icons/128.png /usr/lib/firefox-addons/extension/icons/48@2x.png /usr/lib/firefox-addons/extension/icons/16@2x.png /usr/lib/firefox-addons/extension/icons/32@2x.png /usr/lib/firefox-addons/extension/icons/128@2x.png /usr/lib/firefox-addons/extension/install.rdf /usr/lib/firefox-addons/extension/skin1.jpg /usr/lib/firefox-addons/extension/skins /usr/lib/firefox-addons/install.rdf /usr/lib/firefox-addons/langpacks /usr/lib/firefox-addons/langpacks/ar.moz-firefox-locale-ar.jar /usr/lib/firefox-addons/langpacks/ca.moz-firefox-locale-ca.jar /usr/lib/firefox-addons/langpacks/cs.moz-firefox-locale-cs.jar /usr/lib/firefox-addons/langpacks/da.moz-firefox-locale-da.jar /usr/lib/firefox-addons/langpacks/de.moz-firefox-locale-de.jar /usr/lib/firefox-addons/langpacks/el.moz-firefox-locale-el.