As you may remember, Microsoft is testing an update to Cortana in Windows 10. In the latest Insider Preview build, developers separated Cortana and search in the taskbar by giving them individual taskbar buttons and flyouts. A server-side change adds a new section to the search pane.
If you open the individual Search flyout, you will find a new 'Top Apps' section. It features frequently used apps.
The separate Search feature will be dedicated for searching the web and local files and documents, installed apps. It is worth mentioning that Microsoft has added Enhanced Mode to Search Indexer to make Windows Search faster and more accurate.
The feature seems to be in A/B testing right now, so only select Insiders are able to use it. However, it is possible to force enable it, even if you are not part of that small group.
This can be done with help of mach2. According to its author, Rafael Rivera, mach2 is a third-party tool that manages the Feature Store, a core component of Feature Control, where these switches live. It can display which features are enabled or disabled on a machine. It can also assist with the discovery of interesting features to flip on and off.
For more details, refer to the following article: