How is Akame Ga Kill Zero different from the main storyline?

Akame Ga Kill is certainly one of the starter anime everyone gets recommended to. But what about Akame Ga Kill Zero? Is it any different from its famous counterpart?

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Akame ga KILL! ZERO Manga Volume 1 New Sealed

Akame ga kill zero manga that good? I've startet to read, will it make an anime adaption? : r/AkameGaKILL

Akame Ga Kill Anime Review • Core Reviews

Akame Ga Kill! Zero, Vol. 8 - By Takahiro (paperback) : Target

Manga First Take: Akame ga Kill Zero

Used copy of Akame Ga KILL! ZERO, Vol. 1 by Takahiro; Kei Toru for sale on Pangobooks.

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Chapter 21 (Zero), Akame Ga Kill! Wiki

Akame ga Kill! (TV Series 2014) - IMDb

Akame ga KILL! ZERO Manga Volume 1 New Sealed

Akame ga Kill! Zero - Zerochan Anime Image Board

Chapter 60 (Zero), Akame Ga Kill! Wiki

Akame Ga Kill! Zero Vol. 1 - Manga Review — Taykobon

How is Akame Ga Kill Zero different from the main storyline?