In Spanish, "esos" refers to something that is not in the immediate vicinity of the speaker, but is also not too distant. "Aquellos" refers to something that is a great deal farther away from the speaker and listeners.
ask those childrenpregúntales a esos niños;those ones over thereaquellos de allí;aquellos que están allí;it's not these chocolates but those ones I likeno son estos bombones los que me gustan sino aquellos
In the past the standard spelling for [esos/esas] and [aquellos/aquellas] as pronouns was with an accent ([ésos/ésas] and [aquéllos/aquéllas]). Nowadays the [Real Academia Española] advises that the accented forms are only required where there might otherwise be confusion with the adjectives [esos/esas] and [aquellos/aquellas].
those whichlos que;las que;those wholos que;las que;quienes;those of you/us who ...los/las que ...;I prefer these to thoseprefiero estos a aquellos