A beta version of an independent Cortana app has appeared on the Microsoft Store. The app offers a new conversational experience that was recently spotted in Windows 10 20H1 preview builds. The conversational UI encourages typing over voice and is very similar to the Cortana UI for Android devices. Cortana has always been a part of Windows 10 operating system and Cortana updates are tied to Windows Updates. By moving Cortana to the Store, updates will be shipped to Cortana directly from the Store and this could actually improve Cortana’s usefulness.
Source: https://www.bleepingcomputer.com/news/microsoft/cortana-beta-app-for-windows-10-appears-on-microsoft-store/