An inside bar has a narrower range relatively to the previous bar's range: its High is lower (LH: Lower High) than the previous bar's High and its Low is higher (HL: Higher Low) than the previous bar's Low.
Inside Collection (Course): Technical Analysis Dictionary
An inside bar has a narrower range relatively to the previous bar's range: its High is lower (LH: Lower High) than the previous bar's High and its Low is higher (HL: Higher Low) than the previous bar's Low.