The Everscale blockchain consists of a masterchain responsible for the overall state of the network, workchains, i.e. individual blockchains (their number can be increased linearly) and shards, i.e. segments of the workchain (several shards form a workchain).
TVM is a virtual machine used to execute the smart contract code in the masterchain and in the Workchain Zero. TVM is used in Everscale, Venom, GOSH and TON blockchains.
This is a stacking virtual machine. We operate data in a stack (operations like "sum up 2 topmost numbers in the stack" or "swap the 2nd and the 10th variables in the stack").
Peculiarities of TVM
The TVM, used to run smart contracts in the masterchain and Workchain Zero, is considerably different from customary designs inspired by the EVM (Ethereum Virtual Machine): it works not just with 256-bit integers, but actually with (almost) arbitrary “records”, “structures”, or “sum-product types”, making it more suitable to execute code written in high-level languages.