Internet was earlier used in the MILITARY purpose for making the trajectory of the MISSILES.This was the suitable mode of working as the area fixed by the MISSILE should meet the desired output.Earlier ARPANET was used for MILITARY purpose but it became more hi-tech and had an impact on day today life of a person gradually.
A good example of internet can be ETHERNET.

INTERNET can be classified according to the areas:--

(i) LAN:- You people are familiar with LAN, it stands for Local Area Network.
It is having high speed than MAN or WAN, it is so because the area
covered by LAN is small and thus result in great speed.

(ii) MAN:- MAN stands for Metropolitans Area Network.It covers all metro cities.You might be imagining that how our railway or Airways ticket seat number don't clash???It is due to MAN through which they alot the data in the database .This helps in stopping the repetition of the numbers.They area REMOTELY connected and they have around thousands of remote access at a time.

(iii) WAN:- It stands for Wide Area Network.When you are sitting on internet at that time you are connected widely.You can access the data from far flung places.This helps in making the communication more fast and without any error.There are millions of people connected through the WAN.