There are very simple ways to install Joomla, in fact there are basically two ways to install Joomla.
1. Download a copy of Joomla from http://Joomla.org and install it on your computer offline or on an online hosting server. In plain terms, let refer to your hosting server as your website running online.
2. Install Joomla directly into your online website using script installer in the control panel of the site.
Install Joomla! 3.x on Localhost
Installing Joomla! 3.x. on Localhost is straightforward but can be tricky the first time you attempt it. So for this step we’ve provided instructions on how to do it right from scratch.
First, let’s make clarify the meaning of “Localhost”. As you know, any website needs to be hosted on a web server in order to be shown to users. Normally, you would need to buy a hosting package from some hosting provider. A hosting provider will install a web server for you on one of their server machines, which is accessible to the public. A Localhost is basically the same type of web server but installed on your own computer.
Now, in order to run Joomla, you need not only a web server, but also two more softwares/applications: PHP script interpreter and MySQL database system. It sounds complicated but thankfully, there are packages such as AMPPS, XAMPS, with all the aforementioned elements included.