Concept of Internet
The Internet is the global "Network of Networks," linking thousands of computer networks together.
Because the Internet is a global network of computers each computer connected to the Internet must have a unique address. Internet addresses are in the form xxx.xxx.xxx.xxx where xxx must be a number from 0 - 255. This address is known as an IP (Internet Protocol) address. Below figure 1.1 shows the Internet address.
The above figure shows two computers connected to the Internet; your computer with IP address 1.2.3.4 and another computer with IP address 5.6.7.8. The Internet is represented as an abstract object in-between.
Every computer that is connected to the Internet is part of a network, even the one in your home. For example, you may use a modem and dial a local number to connect to an Internet Service Provider (ISP). At work, you may be part of a local area network (LAN), but you most likely still connect to the Internet using an ISP that your company has contracted with. When you connect to your ISP, you become part of their network. The ISP may then connect to a larger network and become part of their network. So we can say that the Internet is simply a network of networks. Figure 1.2 shows how computer network work.
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, often through a local phone number or dedicated line. The amazing thing here is that there is no overall controlling network. Instead, there are several high-level networks connecting to each other through Network Access Points (NAP).
it is an Interconnection of computers and computer networks using TCP/IP communication protocol.
Because the Internet is a global network of computers each computer connected to the Internet must have a unique address. Internet addresses are in the form xxx.xxx.xxx.xxx where xxx must be a number from 0 - 255. This address is known as an IP (Internet Protocol) address. Below figure 1.1 shows the Internet address.
The above figure shows two computers connected to the Internet; your computer with IP address 1.2.3.4 and another computer with IP address 5.6.7.8. The Internet is represented as an abstract object in-between.
Every computer that is connected to the Internet is part of a network, even the one in your home. For example, you may use a modem and dial a local number to connect to an Internet Service Provider (ISP). At work, you may be part of a local area network (LAN), but you most likely still connect to the Internet using an ISP that your company has contracted with. When you connect to your ISP, you become part of their network. The ISP may then connect to a larger network and become part of their network. So we can say that the Internet is simply a network of networks. Figure 1.2 shows how computer network work.
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, often through a local phone number or dedicated line. The amazing thing here is that there is no overall controlling network. Instead, there are several high-level networks connecting to each other through Network Access Points (NAP).
it is an Interconnection of computers and computer networks using TCP/IP communication protocol.
