Traditional software downloads require a complete (and sometimes lengthy) download before the product can be unpackaged, installed and used on an endpoint computer. Click-to-Run streams Office installs over a network, much the same way YouTube streams videos to website visitors. Streaming allows the end user to open and use Office before the entire software suite has been downloaded. If the end user clicks on a part of Office that has not yet been downloaded, Click-to-Run will jump ahead to that part of Office and make it available. Once the entire download is complete and the software has been installed, the end user can run Office offline.
Click-to-Run uses embedded App-V 5 technology to run Office in an isolated environment. This feature allows multiple versions of Office to run on the same computer. Because the App-V 5 technology is embedded in Click-to-Run, it does not require licensing nor installation of the full App-V 5 client. Click-to-run downloads are reported to use less disk space than traditional software installations and update automatically.
Click-to-Run is an alternative to Microsoft Software Installer (MSI) but does not replace it. For example, Office 2013 is available and licensed as either Office 365 Pro Plus (Click-to-Run) or Office 2013 Pro Plus (MSI). The licensing agreement determines which installation type should be used.