locator

A locator is a reference or mechanism used to identify and locate a resource within a system, environment, or space. The concept spans physical, digital, and informational domains, and in each case a locator provides a stable way to find an item, attribute, or position.

In geographic and physical contexts, locators include street addresses, coordinates (latitude and longitude), or place identifiers used by mapping and navigation services. In inventory and logistics, locator codes designate where an item is stored, such as a bin location, shelf locator, or pallet ID.

In digital contexts, a locator often refers to a URL or other persistent identifier that points to a resource on the internet. Data systems also use locators such as keys, pointers, or URNs to reference records or objects. In web development and UI automation, locators are expressions that identify elements in a document or interface, including IDs, names, classes, CSS selectors, and XPath expressions. The choice of locator affects reliability and performance of automated tests and scripts.

Other uses include design patterns in software, such as the service locator pattern, which abstracts access to services, and general search or indexing schemes where a locator is the key used to retrieve information. Locators play a central role wherever a consistent and efficient means of finding resources is required.