It also performs with Windows Defender on your PC to remove malware that a third-party solution might not identify.
This is an optional feature that is not enabled by default.
It can be enabled from the configs app > Update & security > Windows Defender > Limited Periodic Scanning.
Windows Defender continues to be the default security app on computers where a third-party antivirus solution isnt available.
So, this feature will be enabled by default.
source: www.techworm.net