Welcome to the world of the TLA - Three Letter Acronym 🙂
ESS - Energy Storage System - ok batteries.
LFP - LiFePO4 - Lithium, Iron, Phosphate - The safest of the currently available lithium battery chemistries. Much less likelihood of these going whoosh compared with the NMC (Nickel, Manganese, Cobalt) chemistry that has been widely used in electric vehicles (most EV manufacturers are moving to LiFePO4 now).
DOD - Depth of Discharge - how much of the ESS total capacity you actually use.
Maybe we need a pinned topic with the common TLAs used in solar.