Location data is a term used to describe the physical location of a device, person, or another object. Location data is often collected by mobile apps, websites, and other services.
Location data can be collected using GPS or cell tower triangulation, which can be used to identify where you are on the planet.
Location data can be used to determine where you are at any given moment; this information is valuable to advertisers and marketers because it helps them deliver more relevant ads. For example, if a website knows your location and sees that you've been searching for flights to Hawaii, it might show you an ad for a hotel there.