Due to high load on the network, Ethereum cannot keep up with the pace and scale. As a result, Ethereum foundation implemented updates to the Ethereum Miner software under the name Metropolis. Accordingly, the upgrade has now been split into two parts named Byzantium and Constantinople.
Byzantium. This upgrade includes fixing various scalability issues:
-the problem of difficulty adjustments
-‘returndata’ operations
-‘static call’ operations
-new precompiles
-a difficulty delay feature
These are small tech things which won’t be obvious to non-developers. To be more exact, it will solve smart contract issues like re-entrance attack (when untrusted code enters a contract to manipulate it), return data in receipts will make it possible for light clients to determine if a transaction was successful or not with no need of actually executing the transaction in a virtual machine.
The main aspect of the upgrade is a reduction in Ethereum issuance to miners through block mining rewards from the current 5 ETH to 3 ETH. As well it will delay the increase in mining difficulty which was placed there for the Proof of Stake (PoS) upgrade. PoS is delayed, so to keep issuance around the same level as it should have been.
https://keepingstock.net/ethereum-hard-fork-2x-of-all-tokens-69aaa697e07d
