Kusama is a scalable network of specialized blockchains built using Substrate and nearly the same codebase as Polkadot. The network is an experimental development environment for teams who want to move fast and innovate on Kusama, or prepare for deployment on Polkadot.
Permissionless network which aims to become a testing ground for experiments with significant changes on Polkadot.
Kusama's infrastructure includes the Relay Chain, the Parachains, and the Bridges.
Kusama uses the KSM tokens for network operations. KSM serves multiple purposes such as Governance, Staking, Bonding & Fees