selector

Someone or something which selects or chooses.

There is one selection for hot chocolate. All selectors are the push button type.

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.

The ID selector targets just one element per page, making it much more specific than a class selector that might target many.

The selector indicates the query expression to run over the DOM; the context indicates the portion of the DOM from which to run the query.

A pointer to a structure describing a segment of memory.

Phar Lap executables […] provide a protected-mode selector, 34h, that maps to the first megabyte of physical memory.

You will only have to be concerned with DPMI, selectors, and such, if you use Borland C++ in DOS.

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

Gopher selector strings are more liberal in makeup than URLs and may contain any characters other than a tab, return, or linefeed.