I’m currently upgrading Apple OS X Mavericks as we speak. It’s a huge file, 5.29 GB to be exact. Sit back and relax, because it will take sometime to download the new OS depending on the speed of your internet connection. After the download, launch the installation. It requires a reboot. After boot, expect about 45 mins for the installation to complete.
For those of you waiting for the latest Apple OS X. It’s now free.