What if you don't have hosting account
You can use various offline software packages which can emulate exactly like a hosting environment (webserver).
These tools are free to use. They are good for testing and learning and you don't require an internet connection to test your joomla website! But it has some major drawbacks too. One major drawback is that other people can't see your website! for this you have to buy a hosting space so that whole world can see your joomla websites.
In order to install joomla 2.5+ you need the following requirements in your hosting environment:
To find more detailed installation you can check on the following links: