How Internet works?
In a nutshell, Internet is a network of networks which connects computers to each other and allows to transform data between them. Internet is a huge entity and to understand how it works we will look at it as at the system with key components.
Firstly, you need to have hardware: everything starting from cables to satellites. There are machines data being stored on - servers, endpoints, such as smartphones - clients and connection points - nodes, eg. routers. Between the hardware devices you need to have transmission lines. They can be either physical - optic fibre cables or wireless signals from satellites, cell phone or 4G towers, or radios.
Most large communications companies have their own dedicated backbones connecting various regions. In each region, the company has a Point of Presence (POP). The POP is a place for local users to access the company's network. POPs are connected to each other through Network Access Point (NAP). T1 and T3 in the picture are the types of backbones. For example, T3 operates 45 Mbps (45 million bits per second). The backbones are typically fiber optic trunk lines. The trunk line has multiple fiber optic cables combined together to increase the capacity.
In order to make this data transformation possible and computers “understand” each other there are protocols. Protocols are sets of rules that machines follow to complete tasks. They make the communication between devices possible. There are dozens of different protocols for different purposes. One of most important is, for example, Internet Protocol (IP). It is the pre-defined way that someone who wants to use a service talks with that service. The "someone" could be a person, but more often it is a computer program like a Web browser. There are also IP addresses, so one machine could find another.
Data (also conversation, using voice over internet protocol, VoIP) between machines is transferred in packets. Packets are are parts of a file that range between 1,000 and 1,500 bytes. Packets don't necessarily all take the same path -- they'll generally travel the path of least resistance.
How data travels?
Information through the internet are transmitted by two basic methods: wires and frequency waves through the air. Microwaves are high-frequency waves that travel through the air in order to transmit data. Microwaves can travel directly through the air to each individual host, or are relayed all around the world through satellites.
Satellites
Satellites are used to transfer information through microwaves over farther distances. Satellites orbit approximately 22,000 miles above the earth's surface. Satellites are a means of redirecting straight microwaves from only satellite dish to another. Satellites located all over the world and has the ability to transfer vast amounts of data to almost anywhere in the world.
Satellite Internet generally relies on three primary components: a satellite in geostationary orbit (sometimes referred to as a geosynchronous Earth orbit, or GEO), a number of ground stations known as gateways that relay Internet data to and from the satellite via radio waves (microwave), and a VSAT (very-small-aperture terminal) dish antenna with a transceiver, located at the subscriber's premises. Other components of a satellite Internet system include a modem at the user end which links the user's network with the transceiver, and a centralised network operations center (NOC) for monitoring the entire system.
Microwaves
The information travels through the air and into satellite dishes where the data in decoded and sent through copper lines to a host. Microwave transmission is only of the faster ways to transmit information, but are only useful for distances up to 30 miles. Because microwaves travel in a straight path, the curvature of the earth only allows the information on travel short distance.
Microwave links carry signals which are pulse code modulated (PMC). PMC is a form of digital modulation in which the microwaves are switched on and off in pulses of varying length. The length are arranged in binary code.
