Value types are copied on assignment: `bool`, `uint8`…`uint256`, `int8`…`int256`, `address`, `address payable`, `bytes1`…`bytes32` and `enum`.
`uint` is shorthand for `uint256`, the EVM's native word size, so it is usually the cheapest choice unless several small values can be packed into one storage slot.
uint256 total = 1_000; int256 delta = -5; address owner = address(0); bytes32 root; bool active = true;
There is no floating point. Money is held in the smallest unit — wei for ETH, or the token's own decimals.