When Bitcoin Cash forked from Bitcoin the two coins were – at that time – exactly the same, sharing the same transaction history since the genesis block of Bitcoin on January 3rd 2009. Following the split, the two chains have now gone separate ways, forming their own separate blocks each with a unique set of transactions specific to their blockchain. But the differences go further:
Segregated Witness (SegWit)
Bitcoin Core managed to reach consensus on “Segregated Witness” in July 2017. This software upgrade allowed for additional capacity onchain by safely removing some data from each block. Segregated Witness also resolved the transaction malleability issue that Bitcoin faced, enabling the introduction of lightning networks. Bitcoin Cash has decided not to implement SegWit, and instead will be scaling their blockchain through block size increases.
Development Team
Bitcoin Cash have a few dedicated developers compared to Bitcoin which has a team of Core developers and dozens of interested parties contributing code. In this way, Bitcoin Cash lacks technical expertise, and software upgrades like SegWit and Schnorr Signatures are unlikely to be implemented on BCH.