What does "CSS" stand for, and what is the current state of the CSS standard?
CSS stands for Cascading Style Sheets; it is no longer released as single numbered versions but as a growing set of independent modules, which is why there will never be a "CSS4".
The name has two important ideas baked in. Style sheet means a separate document that describes how content should look. Cascading refers to the rule system that decides what happens when several conflicting styles target the same element (covered in its own card).
A quick history:
| Milestone | Year | What it added |
|---|---|---|
| CSS 1 | 1996 | Basic styling: fonts, colours, simple spacing |
| CSS 2 | 1998 | Positioning, z-index, media types |
| CSS 3 onward | Ongoing | Split into modules (Flexbox, Grid, Animations, ...) |
Since CSS3, the language is developed as separate modules that each progress and ship on their own schedule, rather than as one big numbered release. Browser vendors implement each module as its specification matures. The practical takeaway: treat CSS as a continuously evolving "living standard" where individual features arrive when they are ready.
Go deeper:
Cascading Style Sheets (Wikipedia) — history of the language and how the module-based "living standard" model replaced numbered versions.