What is Internet?

Internet can be defined as the worldwide network where machines like computers, servers, and smart devices are connected together for communication and data exchange purposes. In layman's terminology, the Internet is the network of networks interconnecting computing devices located throughout the world. These networks use some communication protocols to link the network devices with each other.

Internet Architecture

To understand the working of the Internet, it is important to understand the underlying concepts and the infrastructure of the Internet. The two major concepts that run the Internet are (a) the IP address and (b) the TCP/IP protocol suite.

Internet Address

Every computer that is connected to the Internet must have a unique address. This address is called the IP address. IP stands for the Internet Protocol. We can define the "Protocol" as a set of rules. Therefore, the Internet Protocol can be defined as the set of internet rules associated with Internet communication. The IP address can be thought of as a destination's address. For instance, when we need to post a letter, we need the recipient's address. The letter also contains the sender's information. This sender and receiver information on the envelope not only makes sure the delivery of the letter to the correct recipient, but it also informs the recipient about the sender's address. IP address plays a similar role in Internet communication.

There are two types of IP addresses namely (a) Private IP address and (b) Public IP address. The private IP address is an arbitrary IP address assigned by the user. There are three blocks of IP addresses that are dedicated for private use and they are 10.x.x.x (Class A), 172.16.x.x - 172.31.x.x (16 Class B) and 192.168.x.x (256 Class C). For instance, if we open the command prompt and type the ipconfig command, we see an IP address usually ranging between 192.168.1.1 to 192.168.1.254. The private IP addresses are not globally unique as anyone can use the IP address within their own private network (Intranet). The public IP address is a globally unique IP address that is assigned by ISPs. The ISP assigns a public IP address to the network device connected to the Internet either dynamically or statically. The users can check their public IP address through free services like What Is My IP. The current version of the IPv4 addresses is only 32 bit long. That means the current IP assigning system can assign IP addresses to only 2³² (4 billion) computers in the world. To cope with future issues of assigning IP addresses to more internet users, a new IPv6 address assigning system is already introduced. The new system can assign IP addresses to 2¹²⁸ Internet devices.

TCP/IP Protocol Suite

The TCP/IP (Transmission Control Protocol/Internet Protocol) suite is a set of protocols responsible for communication between two networked devices. The TCP/IP protocol suite ensures that the messages transferred over the internet reach to the destination IP address. The TCP/IP is a combination of two protocols (i.e., TCP and IP). The TCP protocol defines the communication channels between the devices. It converts the communication messages into packets, defines the correct format of the packets and arranges the packets in the correct order, and reassembles the packets back into a complete message in the correct format at the destination. The TCP is also responsible for resending any packets dropped during the communication process. The IP is responsible for addresses and routing the packets to the correct destination. It is important to note that not all communications use the TCP/IP suite. The communications where the handshake and acknowledgment are not required usually use the other protocols like UDP (User Datagram Protocol). The example includes live video streaming on the internet.

Internet Security

The communication over the Internet is not 100% secure and anyone on the network can eavesdrop on your traffic. Computers and network devices are vulnerable to different type s of cyber threats. The WanaCry ransomware attack launched in 2017 is a recent example of how attackers can break into our computer systems when we are connected to the Internet. However, some simple precautions can avoid the majority of Internet attacks. Following are some basic precautions that should be followed while surfing the internet.

• Keep your Internet connected device software up to date
• Install any patches recommended by the vendors
• Never install software from untrusted suppliers
• Avoid downloading software from the suspicious websites
• Never click on the email links from the unknown and suspicious email accounts
• Never download the email attachments that you don't trust
• Use antivirus and antispyware to scan your system and applications
• Check your system logs and access permissions of the applications running on your system
• Always use the licensed version of the software
• Use personal VPN to protect your identity and privacy