Google Maps is the best web mapping service in the world.It was first desiigned by by two techie brothers at a sydney based company but was later company was acquired by google in the late october 2004.
Pros & Cons
Pros
Google Maps is well used in various applications because of the well defined APIs by the google and by the people because of the well designed user interface.
Google Maps is currently available as a desktop service and as a Application on all the major mobile platforms such as Android, Ios, WIndows and also in the BB10.
The google web mapping service can still work on the mobile phones apart from the above mentioned which has GPRS or a cellular data connectivity.
This web mapping service can also provide information about the route such as train and bus numbers and their timings.
Google has rolled out a new feature in their mobile application in the november 2015, where users can save the MAPS for offline.
Lastly, what I like most in the googles web mapping application is the street view, where users can have a 3D view of their desired location.
Cons
The major problem with this service is the national security albeit certain places such as white house top and rashtrapathi bhavan are blurred it is strongly advocated to remove all the terrorist targetted places.