Block states

Block states (also known as block properties)[note 1] are extra pieces of data that further define a block, such as how it appears or behaves.

In Bedrock Edition, 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.

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