Aquel (male) and Aquella (female) for singular
Aquellos (male) and Aquellas (female) for plural
Aquel, aquella, aquellos and aquellas are demonstrative adjectives, You use this when someone is pointing, thinking or remembering on something it's not close from the peoples are talking.
Do you remember that house? - ¿Recuerdas aquella casa?
That book was good - Aquel libro era bueno
That cars are big - Aquellos carros son grandes (The cars are far away from the peoples are talking).
Ese, esa, esos and esas are used when peoples point or refer on something it's close to the other person.
Este, esta, estos estas are used when peoples point or refer on something it's close to the person it's talking
I'm going to use two peoples (Carl and Lenny) and one book in three different situation. Whit the sentence "That book is new"
First scene: The book is near to Lenny. It's on the Lenny's desk.
Carl says: Ese libro es nuevo
Second scene: The book is near to Carl. It's on the Carl's desk
Carl says: Este libro es nuevo
Third scene: The book is away to Carl and Lenny it's on other desk
Lenny or Carl say: Aquel libro es nuevo.