The name is based on the game rogue from way back in the day, a roguelike is really just any game that has a gameplay loop where you completely reset without any carryover of items or skills, and a roguelite is the same but there will be a small amount of carryover of skills or items or something like that. For instance the binding of Issac is a popular roguelite, you lose all your items when you restart but you can unlock characters that persist even if you die.