Block states

Block states (also known as block properties) are extra pieces of data that further define a block, such as how it appears or behaves.

$$, there are also aux values (also known as Metadata) to define a block. Aux values are in the format of binary flags, which basically match the block states one-to-one. And they are accessible in decimal number in commands. However, aux values are intended to be deprecated, and newly added blocks or block states no longer support aux values.

$$, there are also fluid states, that further define a fluid as to how it behaves.

History
Blockzustand Valeurs ブロック状態 블록 상태 Estados de bloco Состояния блоков 方块状态