Its a "SERVICE" based idea. No one is full of knowledge in all things. A person wants to go Delhi First time which he doesnot know nothing about that area.
He just to know reserved the Train Tickets, but what about form home to railway station and what available sources in Delhi. Here the "SERVICE" works.
That person contacts the "SERVICE" .it provides every thing like taking from home, shows the Reserved Seat, providing food (as per his menu) and arranged everything in Delhi for his like, Boarding, lodging and etc in his budget only(In Delhi There The "SERVICE" branch works for this). In All Over World every where the branches of "SERVICE" is ready to service for this. Its not only for like this type of service but also about Law needs, Shopping , to show the Government and private orginasations offices(legal things only) etc. Every each simple things available in this "SERVICE" . For this "SERVICE" charged some amount but works with honaurable and patiently explain to everything to cumstomer.