Bitcoin's prominence and capabilities are fantastic. Proof of Work by bruteforce getting exponentially harder over time. There are a lot of mining operations, the reason we call upon decentralization as a method of value extraction is due to the diverse crowd running these servers and software. Value accumulation occurs due to the network propagation and acceptance supporting the creation and use of any chain. Doesn't solve all the right problems yet, though has the namesake for cryptos until further notice.

Steem uses weighted upvotes as their inflationary measure distributing network incentive for the propagation, usage, and steak increase in the STEEM blockchain, based on the amount of steem power a user wallet has locked into the ledger. It then distributes new tokens based on the rules detailed in the steem bluepapers. Instead of brute force calculations, we have bot and human upvoting.

Therefore Steem is mining for steak weighted votes, where bitcoin is mining for the next block number. Of course bitcoin has and will continue to be forked such that some of it's network value is maintained and active user accounts exchange securely as intended.

Witnesses run the servers which maintain the steem blockchain, steemitbuzy website provides a portal into the exchange of information as value like miners need electricity to mine with bitcoin farms. Not that steem doesn't need electricity and network strength but it is not at the same network scale as bitcoin yet.

Stemians are Mining for Weighted Votes!