Source:
http://en.calameo.com/read/005253436ac45146ad375
Global positioning system (GPS) technology allows people to track objects and determine exactly where they are at any given time. Sometimes, GPS technology delivers tracking information after the fact, meaning it is delayed and not current. When current information is delivered while the tracking is happening, this is referred to as real time GPS tracking. This type of tracking is very popular for use with cell phones and vehicles, and it may have other uses as well. Unfortunately, the technology isn’t always used in a legal manner and is sometimes the subject of controversy.