The practical benefit of Demux is allowing blockchain events to be automatically (and verifiably) updated to a Mongo or Postgres SQL database. This will make dealing with the database easier, as more people are familiar with these packages, and cheaper, given the fewer interactions with the main ledger. Here is the visualized example, provided by Block.One:
All of this functionality may sound like something very basic to those, experienced in traditional coding, but when operating with blockchain nodes, the situation is quite different. According to the EOS announcement, the prior interface was quite limited. This had the negative effect of requiring multiple simple queries, instead of a single more complicated one, which is a big issue if scaling is a factor.
If this all sounds a bit too complicated for some of you, the simplest way to explain the story will be “EOS applications will be easier to develop with this feature”. The continuing improvements to the EOSIO blockckchain are the main reason the Chinese Center for Information Industry Development (CCID) gave the project the number one spot, for the second month in a row in their July rankings.