LOQO 1 and 2 are their own games. The first is set in Egypt, and the second in an alternate dimension, with a brief visit to Egypt. It's more or less a direct sequel, but the MC changes (in all games), and the connective thread is sort of tenuously through Opala and her family.
Origins is in the same alternate dimension as 2, and due to time fuckery it's sort of sequel and prequel at the same time. The talk of Episodes is down to Gabe sort of loosely defining phases of each game as separate episodes. There's no real distinction, and the games are, at least eventually, a single release containing all the episodes. Origin's releases/files have never been split up by episodes, but I *think* 2 was briefly.
Origin is currently in Episode 3, and has been since like 2018. Gabe's original plan from 2013 was that Origin would be released in 3 episodes, each taking about a year to complete.