The Stacks blockchain enables a user-owned internet connected to Bitcoin. Bitcoin is the most durable and secure blockchain that is minimal by design. Stacks extends the design of Bitcoin to enable smart contracts and applications without modifying Bitcoin, and with minimal transaction load on Bitcoin. Thousands of Stacks transactions result in a single hash on the Bitcoin blockchain, and Stacks microblocks offer fast confirmations of streaming blocks.
The Stacks cryptocurrency (STX) is used as fuel for smart contract execution, transaction processing, and digital identity and asset registrations. STX is a unique crypto asset that can also be locked by STX holders to actively participate in consensus and earn Bitcoin (BTC) rewards.
STX is a yield generating asset when used in consensus and functions as a utility token when consumed as fuel. Stacks cryptocurrency was distributed to the general public through the first-ever
SEC qualified token offering in US history.
For a recent overview of the Stacks ecosystem see this
July 2020 update presentation slides.