This means that it is a temporary folder created by windows, and sometimes it will automatically delete after 10 days of successful Windows update. First, you need to enable the hidden items to view this folder. This folder is created by Windows Recovery Environment during the windows update or upgrade process, it stores the temporary recovery files that help WinRE to recover or rollback the windows OS if there is any failure during the update process.
It contains temporary files that allow you to recover Windows 10 if there is any problem during the windows update process. WinREAgent is a folder which usually created automatically during an upgrade or update process.