What is the meaning of Selector?

Someone or something which selects or chooses.

An administrator responsible for selecting which players will play for a side.

A matching expression in a stylesheet determining which elements in the markup are affected by a style.

A pointer to a structure describing a segment of memory.

A text string transmitted to a Gopher server, identifying the resource to be retrieved.

A disc jockey.

A person who is entitled to choose a tract of Crown land to purchase.

selector

selecting

selector

Source: wiktionary.org