Hardfork 26 is the next version of Hive, it's an update that'll make the chain better and more efficient.

@themarkymark explained the features in a simpler way on his post.

Some of the improvements include:
One Block Irreversibility
Increasing HBD haircut ratio
Allow more than one vote per block
Remove vote change penalty
Support for block log compression
Peer to peer performance improvements
Resource credit overhaul
Resource credit delegation
General improvements to improve operation handling