What is a grid locator?

A grid locator, also known as a Maidenhead grid square, is a standardized geographic coordinate system used by amateur radio operators to concisely communicate their location. It uses a sequence of alternating letters and numbers to divide the Earth's surface into progressively smaller rectangles. Grid locators are especially popular in VHF/UHF operations, satellite communications, and digital modes like FT8. They allow stations to quickly share their location using just a few characters, which is much faster than exchanging full latitude and longitude coordinates. It is not a tool used for aiming an antenna, nor is it a piece of physical hardware or testing equipment.