In Firefox, you can have more than one web page open at a time. Tabs are used to allow you to do this. The tab bar should display at the top of your browser window and this is how you navigate between web pages. Each tab listed on the tab bar is a different web page.

Some websites request to open their content in a new tab, so this is why you have multiple tabs. You can close off a tab by pressing the little close button on each tab. This will only close the selected tab, compared to using the browser close button and closing all tabs.

For more information on using the Firefox tab feature, please refer to this Mozilla support article:

• Use tabs to organize lots of websites in a single window

If you would still like to disable tabs in Firefox, you can try changing the setting with these steps:

1. Open the Firefox options
2. Navigate to the General section on the sidebar
3. Uncheck Open new windows in a new tab instead

More information on these settings can be found in this Mozilla support article:

• Tab preferences and settings

Note: This may work in many cases, but since the option to open a tab is largely controlled by the website, some web pages may still open a new tab instead of a new window.

You can set this pref to false on the about:config page to prevent closing Firefox when you close that last tab.

• browser.tabs.closeWindowWithLastTab = false

Note that the Back button can be disabled if you open a link via some built-in (xul) pages like the about:newtab page.