The term upgrade refers to the replacement of a product with a newer version of the same product.
In the world of information and technology each technology improves day by day in terms of speed and features, so the new technology will replace the old one.
The same rule will apply while working with magento, because day by day newer versions of magento have been found with better features.
To use the new features of magento, store owners are required to upgrade their store with the latest magento version.
We can upgrade the magento full version via SVN or by using Magento Connect Manager, but it is better to use Magento Connect Manager to upgrade.
The steps to upgrade magento store using Magento Connect Manager is as under:
Step1: Login to your magento admin.
Step2: Go to System -> Magento Connect -> Magento Connect Manager from the header menu.
Step3: Login to your Magento Connect Manager with same username and password, which are used for admin login.
Step4: Click on Check for Upgrades button.
Step5: Select the “clear all sessions after successful install or upgrade” option.
Step6: Select the upgrade to latest version action from the action combo box for the magento core packages.
Step7: Click on “Commit Changes” button, and it will upgrade your magento store packages to the latest versions.
Hope this will help you.