Antivirus software relies on two things: the engine (the software itself) and the definitions (the database of known threats). While 360 is generally good about providing definition updates to older engines for a period, there comes a point where the engine architecture is too old to support the latest definition formats. Running a build from several years ago might mean you are missing out on heuristic detection methods designed to stop modern ransomware
This "Essential" version focuses on core security rather than the full optimization suite found in the standard version: Older versions of 360 Total Security Essential (Windows)