Accretion ○ ❪✺ᵢ❫ Accretion Concepts ○ ❪✺ᵢ❫ Accretion Concepts ○ ❪✺₁ᵢ❫ Accretion Classes ○ ❪✺_ᵢ❫ Accretion Subs ○ Advection-Dominated Accretion Flow (ADAF) ○ Geometric Thickness ○ Magnetorotational Instability (MRI) ○ ❪✺₁ᵢ❫ Accretion Classes ○ Accretion Disk ○꠹ ❪✺_ᵢ❫ Accretion Subs ○ Accretion Disk Corona ○꠹