Though, "abajo" and "debajo" are used indistinctively by native speakers, "abajo" is related to motion, whereas "debajo" refers to a position. Pretty much the same difference in English with "on" and "onto". I can say "the water is on the table" (the place where the water is), and I can say "the water is being poured onto the table" (where the water is going to). Examples: El computador se fue abajo = the computer went down. El computador está debajo del escritorio = the computer is under the desk. As for "bajo", it is an adjective, (not an adverb like "debajo" and "abajo") meaning "short". Example: El niño ya tiene 8 años, pero es bajo para su edad = the kid is 8 years old, but he is short for his age. I hope this helps.

Abajo: something that is lower Debajo: it has something above Abajo: parte inferior Debajo: respecto de algo que esta encima

"Debajo de..." is relative. Thigs are "debajo de" other things. It can be translated by "under...". It is what we call a "locución prepositiva" and it works just like a preposition: "The ball is under the table" = "La pelota está debajo de la mesa". Sometimes, we use "debajo" as an adverb. In this case, it can be translated by "under it" in English: "Do you see that table? The ball is under it." = "¿Ves esa mesa? La pelota está debajo." "Abajo" is an adverb. It means "the place below" or "the lowest part". In a house or building, it will ususally mean "downstairs". "La cocina está abajo" = "the kitchen is downstairs". If you are in a high place, like a mountain, hill, etc., you will say of things/people who are at ground level that they "están abajo". It can also mean a direction: "down". "The elevator is moving down" = "Es ascensor se está moviendo hacia abajo". Sometimes, you may see "abajo de" instead "debajo de". It is less common, but correct. The other uses of "abajo" and "debajo" are distinct, though. There's also the preposition "bajo". It's used like "debajo de" and it means the same: "La pelota está debajo de la mesa" = "La pelota está bajo la mesa" The adjective "bajo" means "short", but that's not related to your question.