Light

Light (or lighting) in Minecraft is a game mechanic that affects visibility, mob spawning, and the growth of some plants. There are three aspects of Minecraft's lighting system: light level, internal light level, and rendered brightness.

Light levels can be found on the debug screen in Java Edition next to "Client Light" in parentheses. There exist two main types of light: sky light and block light. Other types of light, not present on the debug screen, are explained in the internal light level section. The term light level may be used to refer to the value of any of the light types.

There are 16 light levels, specified by an integer from 0 (the minimum) through 15 (the maximum).