This was the source of the first great frustration. You had to download gigabytes of data from Microsoft’s servers using that key. If your internet was slow, you were out of luck. The key was your proof of purchase, but it was fragile. Once you used it, it was "consumed."
Office 2013 was designed with mobility in mind, offering better support for touch devices and the inclusion of Office apps for iOS and Android, which broadened the software's usability across various platforms. microsoft office 2013 key