• The position of a box on the z-axis, relative to other stack levels within the same stacking context. The CSS z-index property can be used to define the stack level of the respective box in the current stacking context.

1. Related terms: Stacking context, Solution stack, Call stack, Block-level box
2. Previous term: Stack frame
3. Next term: Stack Overflow
4. Random term: Hypertext Transfer Protocol (webglossary.info/random 🎲)