‫So let's look at the basic concepts of networking and, of course, the mother of all networks, the
‫internet.
‫The internet is a global system of interconnected computer networks that use the standard internet protocol
‫suite, often called TCP IP, although not all applications use TCP to serve billions of users worldwide.
‫It's a network of networks that consist of millions of private public, academic, business and government
‫networks of local to global scope.
‫That are linked by a broad array of electronic wireless and optical networking technologies.
‫The internet carries an extensive range of information, resources and services, such as the interlinked
‫hypertext documents of the World Wide Web, W WW and the infrastructure to support email.
‫The origins of the internet reach back to research done in the 1960s.
‫Commissioned by the United States government in collaboration with private and commercial interests
‫to build robust, fault tolerant and distributed computer networks.
‫The primary precursor network, the ARPANET, initially served as a backbone for interconnection of
‫regional, academic and military networks in the 1980s.
‫The funding of a new U.S. backbone by the National Science Foundation in the 1980s, as well as private
‫funding for other commercial backbones, led to worldwide participation in the development of new networking
‫technologies and the merger of many networks.
‫The commercialization of what was by the 1990s and international network resulted in its popularization
‫and incorporation into virtually, I'd say, every aspect of modern human life.
‫So as of 31st December 2017, more than four point one billion people, nearly 55 percent of the whole
‫world population use the services of the internet.
‫Now I'll put that in a little perspective here.
‫It's 95 percent of North Americans and about 85 percent of Europeans are internet users.
‫Now, before talking about the internet protocol or what we call IP.
‫We should know what a protocol actually is.
‫A protocol is simply a set of rules governing how things work in a certain technology.
‫So that there is some kind of standardization.
‫Protocols are also typically in charge of sending the right data to the right PC, making sure the data
‫gets to the right program, as well as organizing the data to be sent.
‫Protocols are to computers, what languages to humans?
‫For instance, this course is in English.
‫To understand it, you must be able to understand English.
‫So similarly, for two devices on a network to successfully communicate, they must both understand
‫the same protocols.
‫So I know we're going to talk about this in detail later, but we'll talk a little bit now about IP
‫to better understand the internet.
‫Internet protocol IP describes how data packets move through a network.
‫So when you have a protocol, you are sure that all machines on a network or in the world when it comes
‫to the internet, however different they might be.
‫Speak the same language and can integrate into the whole framework.
‫The IP protocol standardizes the way machines over the internet or any IP network forward or route their
‫packet based on their IP addresses, so along with addressing, routing is one of the main functions
‫of the IP protocol.
‫Routing consists of forwarding IP packets from source to destination machines over network based on
‫their IP addresses.
‫An IP address is a unique address, identifying a machine which can be a computer server, an electronic
‫device, a router, a phone, you name it on a network, thus serving, routing and forwarding IP packets
‫from source to destination.
‫Basically, every computer connected to the internet is given an IP address by the internet service
‫provider, and the computer becomes accessible to others via this IP address.
‫So let's see what the internet looks like on its most basic level.
‫Here we have a home network with a router given by the internet service provider or ISP.
‫Remember that modem that's given to you by your ISP and the devices it connects to the internet?
‫This is a corporation with a lot of end user computers and servers as well.
‫There's a public body here again with a lot of servers and a lot of end user computers.
‫Here is a hosting company with a Web server farm hosting to their customers.
‫Now here's a cloud providers such as Amazon Web Services hosting a lot of servers again.
‫And here there's another home.
‫And they're all connected to each other over telecom company routers.