Firefox update on Linux are often disabled which makes it only applicable via manual update.
So for you to update it you need to type some series of lines on the console. Here are the lines you need to do so:
For Ubuntu/Debian Distro, you can use
$ sudo apt-get update $ sudo apt-get install firefox
For a Fedora/RedHat/CentOS Distro, we need to use the
# yum update # yum update firefox
The following installation assumes that you have a fine and working network connection.