High Magic vs Low Magic comes from Western magical divisions that can be traced back to Greek antiquity.
Theurgy/Astrology (the magic of the heavens and heavenly spirits) vs Goetia/Pharmakeia (the magic of the stuff of the earth/cthonic spirits).
This division was kept through the centuries with some alterations, where in modern Western Esoteric Tradition what is High Magic = Astrology, Ceremonial Magic (both demonic and angelic), etc, while Low Magic = Systemic Correspondence of material things (eg Basil is assigned to Mars), Sympathetic Magic (eg using dolls to affect people’s lives), and etc.
So a lot of Modern Occultists disparagingly refer to European Cunning Craft, Amerindigenous Traditions, African Religions, Asian Shamanism, East Asian Traditions as “low magic”.
Ironically Necromancy is historically Low MagicYour fortune: Excellent Luck