When you buy an Android smartphone or tablet, the software version natively installed on the device may be out of date. In most cases you have the possibility to update the OS of your device and benefits from new features. The procedure is as follows:
Go to Settings > About phone.
Select "Update Firmware/ System Update".
Your smartphone will tell you if any update is available or if your devices is running the latest software version .
If an update is available, you will be able to download it.
In most cases, updates can only be achieved over Wi-Fi (to avoid extra data charges).
Note that: It should be noted that depending on your smartphone model/specs you won't necessarily have access to the recent updates (E.g not all of the latest smartphone are compatible with Android 4.4 Kit Kat).
If you don't have a direct access to the latest Android updates, you can proceed to a manual installation.
The procedure is almost the same for most models:
Download the software suite for your mobile device (available on the manufacturer's website).
Once installed, launch the software and connect your smartphone to your computer via USB.
The software will search for available updates.
Click on the Update button and follow the on-screen instructions.