Select the Site menu option in Joomla 2.5 back-end. Then down to Global Configuration. Now select the System menu tab. Scroll down and to the right. Under Cache Settings we can control the site caching like turning it on or off.
Let’s select the Cache dropdown list and turn caching on. Select the Cache Time field and change it to 30 minutes. Be careful not to set your Cache Time too high. This may have a detrimental effect on your site.
Scroll up and select the Save & Close button. You now know how to enable Caching in Joomla 2.5.