What is an EVM?

State of the World
All of the addresses and their account states are mapped in the world state trie. The execution of transactions continuously updates the global state. The account storage trie is contained in the leaf node of the world state trie (linked via the storageRoot which points to the root node in the acount storage trie). The nonce, balance, storageRoot, and codeHash columns make up the account storage trie, which contains information on accounts. The stateRoot, which is kept in each block, is the source of the world state.



Transaction Trie The transactions in Ethereum are stored in the transaction trie. The transactionsRoot, which is kept in each block, is the root of the global state.
The Ethereum Virtual Machine controls the rules for switching the Ethereum system's states (EVM). The EVM is an intrinsically cost-constrained Turing complete virtual machine (gas). Between the running machine and the running code is a layer called the EVM.



On Ethereum, programmes are created in a higher level language called Solidity, which is then translated into opcodes, which are a collection of straightforward instructions to carry out a particular activity. Opcodes include:

Mathematical operations and comparisons like ADD, SUB AND, OR
Memory- and storage-manipulating commands like MLOAD and MSTORE Program counter-related commands like JUMP
stopping with STOP, RETURN, or INVALID


plus others. The EVM uses the opcodes' bytecode encoding for execution.