It is just a group of computers connecting to each other.
Here is a simple answer to the question about who provides the Internet to ISP companies.
Peering
Most of the big ISPs use this method.
When ISPs peer they open their own networks to users of the other ISP.
Its donefor free: no ISP pays the other.
IP-transit
Most small data providers opt for IP-transit.
As IP-transit involves carrying Internet traffic between continents and connecting to many other ISPs,its a paid service.
The ISP pays for the volume of traffic carried by an IP-transit carrier.
So, what internet Tiers are there?
The huge networks who provide the Internet to ISPs are known as Tier 1 networks.
By this definition, a tier 1 connection is a transit-free connection that peers with every other tier-1 connection.
But not all transit-free networks are tier 1 networks.
It is possible to become transit-free by paying for peering or agreeing to settlements.
When two mid-sized networks connect to each other through a process known as peering.
Large companies can also go out and arrange their own peering relationships.
To put all the above mumbo jumbo in simple words.
Tier 1 data companies are internet backbones that connect with each other.
Smaller ISPs work with these internet backbones and then sell bandwidth to their users.
No one really owns the internet as it comprises millions of servers everywhere.
source: www.techworm.net
