This property defines the Unicodes which belongs to Hangul Jamo block
Characters like ᄀ,ᄁ,ᄂ, etc. are listed under Hangul Jamo Block.
256 Characters are present in Hangul Jamo Block starting with the Unicode point U+1100 that represents the character ᄀ.
Currently, as per latest version 15.0.0, Unicode supports 328 number of Block. Here are a few examples - Latin Extended E,Adlam,Aegean Numbers, etc.