Selector ↔ CSS Syntax to define pattern to match HTMLElement instances (& special states) in document to direct Style Rule

Source: w3c.github.io/csswg

aka CSS-Selector

Simple Selector

CSS Selector to match on single condition

Grouping Selector

Combinator

Pseudo Selector

Pseudo-Element

Selector :: postfix to match part of selected element(s)

Pseudo-Class

Simple Selector : postfix to match special state of selected element(s)

References

1. Style Rule ↔ Ruleset with Selector & CSS Declaration block

2. Pseudo-Element ↔ Selector :: postfix to match part of selected element(s)

3. Descendent Selector ↔ Selector for Descendant Element (rel to other Element)

4. Adjacent Sibling Selector ↔ + Selector for Sibling Element; E1 + E2 {} where E2 is selector target

5. General Sibling Selector ↔ ~ Selector less strict Adjacent Sibling Selector; E1 ~ E2 {} where E2 is selector target

6. Child Selector ↔ \> Selector for direct Child Element

7. Class Selector ↔ .myClass Selector to match any HTMLElement with class attribute

8. Type Selector ↔ Selector to match all instance by typeof HTMLElement node in Document

9. Specificity ↔ Weighting Algorithm for Layout engine to choose which competing Selector Style Rule to apply to HTMLElement

10. List Selector ↔ , comma separated list of Selector to share & reuse Style Rule

11. ID Selector ↔ #myID Selector to match single unique Element

12. Simple Selector ↔ CSS Selector to match on single condition