It's basically the people we vote for to validate transactions and ensure that everything that happens is recorded on the block chain. That's how I'd describe it anyway.
Technical
As @albensilverberg stated, the main task for witnesses is to maintain a working node and to sign blocks that will be added to the blockchain.
Financial
Witnesses can tweak some financials parameters of the platform.
For example, they have to regularly publish a price feed that allow to compute conversion between STEEM and SBD
Social
Witnesses are kind of ambassador for the blockchain and can promote it by either doing advertising/public relation or by developing tools that will help its adoption.
There are several posts on steemit that cover the witness roles in more details.
It's basically the people we vote for to validate transactions and ensure that everything that happens is recorded on the block chain. That's how I'd describe it anyway.
Witnesses have 3 roles:
As @albensilverberg stated, the main task for witnesses is to maintain a working node and to sign blocks that will be added to the blockchain.
Witnesses can tweak some financials parameters of the platform.
For example, they have to regularly publish a price feed that allow to compute conversion between STEEM and SBD
Witnesses are kind of ambassador for the blockchain and can promote it by either doing advertising/public relation or by developing tools that will help its adoption.
There are several posts on steemit that cover the witness roles in more details.