The User Activated Hard Fork (UAHF) is a proposal to increase the Bitcoin block size scheduled to activate on August 1. The UAHF is incompatible with the current Bitcoin ruleset and will create a separate blockchain. Should UAHF activate on August 1, Coinbase will not support the new blockchain or its associated coin.
The User Activated Soft Fork (UASF) is a proposal to adopt Segregated Witness on the Bitcoin blockchain and could result in network instability. It is scheduled to activate at the same time as the UAHF.
Big Block Chain has overwhelming support from actual bitcoin users. Check out this poll that can't be sybil attacked:
https://vote.bitcoin.com/arguments/the-bitcoin-abc-client-and-big-block-fork-bitcoincash-is-a-better-roadmap-than-both-segwit-and-segwit2x
Good article