A　comprehensive　understanding　of　the　optical　properties　of　atmospheric　aerosol　is　essential　for　a　variety　of　applications,　such　as　optical　imaging,　optical　communication,　and　remote　sensing.　In　recent　years,　many　theories　and　numerical　simulation　methods　have　been　developed　to　connect　aerosol　physical-chemical　properties　to　their　intrinsic　and　integral　optical　properties.　Usually,　simulations　and　measurements　are　intertwined　to　synergistically　attain　the　retrieval　of　aerosol　optical　properties　and　mitigate　or　even　eliminate　the　adverse　impacts　of　aerosol　during　imaging,　sensing,　or　communication.　This　review　covers　the　fundamental　theories　of　aerosol　optical　properties,　the　development　of　numerical　simulations,　the　instrument-based　sampling　measurements,　and　the　cutting-edge　techniques　of　remote　sensing.　Numerical　simulations　have　been　progressing　from　symmetric　particles　to　asymmetric　particles　over　the　past　two　decades,　although　any　simulation　method　is　limited　by　specific　shape　and　a　restricted　size　parameter　range.　Thus,　this　review　also　examines　the　most　typical　advances　in　aerosol　instrumentation　that　are　frequently　used　to　measure　the　intrinsic　optical　properties　of　unknown　aerosols.　Such　obtained　properties　validate　simulations　and　constitute　the　basis　of　integral　optical　properties.　In　terms　of　practical　applications,　integral　optical　properties　are　the　most　critical　knowledge　about　atmospheric　aerosol.　Remote　sensing　measurements,　be　it　ground-based,　airborne,　or　satellite-based,　all　retrieve　integral　optical　properties　of　atmospheric　aerosol　from　various　perspectives,　which　are　elaborated　upon　in　this　review.　In　conclusion,　this　review　provides　an　all-encompassing　comprehension　of　aerosol　optical　properties.