What is the Internet?
The Internet is a vast network of independent computer networks that are linked together to serve billions of users via the standard protocol TCP/TP (Transfer Control Protocol/Internet Protocol). The Internet is a network composed of thousands of private, public, commercial, academic, and government networks.
A variety of wireless and optical networking technologies connect the Internet to our local area. The Internet is an information superhighway. The primary goal of the Internet is to facilitate information sharing.
Before we get into internet services, let's look at some internet facts that will blow your mind.
- Father of the Internet: Vinton Gray Cerf: The co-designer of the TCP/IP protocol suites and the architecture of the Internet.
- The inventor of the Internet: Robert Elliot Kahn and Vinton Gray Cer
- The Internet is not in the control of anyone.
- There are 4.39 billion internet users in 2019 AD which is increased to 366 million versus January 2018.
- There are 3.48 billion social media users in 2019, with the worldwide total growing by 288 million versus 2018.
- Internet uses the standard Internet Protocol (TCP/IP).
- Every computer on the internet is identified by a unique IP address.
Services of Internet /Internet Services
Some of the most popular internet services are :
- Communication Services
- Information Retrieval Services
- World Wide Web Services
- Web Services
- Directory Services
- Automatic Network Address Configuration
- Network Management Services
- Time Services
Let's explain each of them in brief.
1) Communication Services:
Communication is one of the most popular internet services. Every day, we use internet-based communication services to stay in touch with family and friends. It is also referred to as Internet Telephony. Instant Messaging, Internet Telephony, VOIP, Email, IRC, Videoconferencing, and other internet communication services are available. Let's take a look at them one at a time.
a) Instant Messaging
Instant Messaging (IM) is a type of online chat that offers text communication over the internet in real-time. Because of its real-time nature, it is continuously becoming one of the fastest-growing forms of internet communication services. There are many instant messengers that are providing instant messaging. Some of them are Facebook, Whatsapp, Skype, hangout,qq, WeChat, etc. Among those, Whatsapp has the highest number of users actively engaging (report gathered from stattube youtube channel).
Email stands for Electronic Mail. It is a paperless method of sending messages(text, files, or images) from one person to another or many people at the same time using the internet. In 1996, there was more e-mail than postal mail being sent.
Some of the important features of email are :
- Instant Communications.
- One to One or One to many communications
- Free and easily accessible, only required is internet connections.
Some of the most popular email service providers are Gmail, Microsoft Outlook, AOL mail, Zoho mail, fast mail, hush mail, mail.com, MSN, Yahoo mail, etc.
c) Internet Telephony and VoIP
We used to send phone calls, faxes, and voicemails over landlines in traditional telephony, but in Internet Telephony, we do it over the internet. In internet telephony, our analog voice is converted into digital voice (binary form), which is then transmitted over the internet as IP packets from one phone to another. As a result, voice packets are transferred across the network in this case. Internet telephony is also known as IP telephony (IPT).
VoIP is a subset of IP Telephony. It is just a technology used by Internet Telephony for digitizing the analog signal.
d) Video Conferencing
Video Conferencing is Internet Service where two or more people located in separate geographical locations do live audio-video communication. So, it is real-time conferencing services of the internet. For proper functioning of the Video Conference, it may require a high bandwidth of the internet at the sender and receiver sides.
The basic requirement for performing good Video Conferencing:
- Good Internet Connection at the sender and receiver sides.
- Webcams on both sides(sender and receiver).
- Computer screen, TV, projector for displaying video.
- Good video conferencing software like Webex Meetings, ClickMeeting, Zoom, BlueJeans, Join me, Zoho, Skype, Team etc.
e) List Server (LISTSERV)
List Server Sends content-specific emails to a group of email recipients.
Internet Relay Chat, or IRC, is a protocol that allows computers connected to the internet to communicate in real-time via text chat. Private messages between two users, data transmission and other server-side and client-side instructions are all supported, although channels are the primary mode of communication in IRC.
2) Information retrieval services:
One reason why a computer network such as the Internet has been created was, to allow users to access remote computers and transfer files from one machine to another. This internet service includes FTP, FTPS, SFTP(Simple File Transfer Protocol), Telnet, SSH File Transfer Protocol, Trivial File Transfer Protocol, etc.
FTP stands for File Transfer Protocol. Uploading and downloading files is the primary function of FTP, an internet utility software. In order to transfer files and folders across various computers, FTP provides the ability to access distant computer directories. FTP has a client-server system design in which the client and server each have their own set of controls and commands.
If you want to upload a file from your computer to a remote server you need an FTP client. There are numerous FTP clients available. Some of the popular FTP client software are FileZilla,WinSCP,Cyberduck,CuteFTP,Transmit , FireFTP, SmartFTP etc.
Objectives of FTP :
- It promotes the sharing of computer files, folders (directories), and software.
- It helps to transfer data reliably and efficiently.
- It is Faster than other protocols like HTTP or POP so it is a preferred method of exchanging files. It can easily transfer large files.
SFTP stands for SSH File Transfer Protocol. Sometimes it is called Secure File Transfer Protocol.SFTP is a more secure method of transmitting data than FTP. In addition to the SSH key, it provides protection and authentication for the entire SSH protocol. SFTP, for example, is used to access your email because it requires a username and password to gain access to the server's data.
WinSCP is the best software for SFTP.
c) Telnet (Remote Computing)
Telnet stands for Telecommunication Network. Telnet allows the client to log in to the remote server for accessing remote resources. It uses TCP port 23. It is not much secure. We use Putty software for getting remote access to the server. In windows OS, when you type telnet remote_ip in run(Win + R) windows, then enter username and password for remote access then you will be successfully connected to the remote server.
FTP is used for file transfer to/from a remote server but Telnet is used for accessing remote resources. Configuration of remote servers can be done from the client-side.
SSH stands for Secure Shell. Secure than Telnet.Same work as Telnet.SSH sends all the data in an encrypted format. It uses a secure channel for transferring data and commands over the network.SSH uses High bandwidth.SSH can be considered as a replacement for telnet.
Some of the other popular information retrieval services are Gopher, Archie, and WAIS.
Gopher: Gopher is a simple file retrieval application that relies on hierarchical and distributed menus stored on remote web servers.
Archie: Archie is a program that searches the files of all Internet FTP servers that provide anonymous FTP.
3) WWW (World Wide Web)
WWW is one of the main services of the internet. Most of us think that the Internet and WWW are the same but actually not. The Internet is Infrastructure and the Web is just a service provided on the Internet. The Internet is a network of networks and the Web is just information present in the network.
The inventor of the Web: Tim Berners Lee and Robert Cailliau.
There are a wide variety of programming languages used to create various apps. A variety of programming languages and frameworks were used to construct these applications. For any reason, we may need to communicate with each other. It's at this point that web services come into play. Regardless of the programming language used to develop the apps, web services provide a common platform for different applications to connect with one another.
As a result, it serves as a standard medium for passing messages (data) between a client application (created with android, vue, angular, react, or any frontend language in general) and a server application (created with java,.net, python, or any frontend language in general) on the World Wide Web.
In our traditional web application, when a client requests information from the server, the server responds by sending pages as well as data. However, in web services, data is returned from the server to the client in JSON or XML format. This format is then usable by any client application, such as angular, android, vue, react, and so on. This format is independent of programming languages.
Web services are classified into two types:
i)SOAP web services (It uses XML form of data)
ii)RESTful web services. (It can use HTTP,JSON,URL , XML form of data)
Some other services of the internet include:
5) Directory Services ( like DNS, LDAP )
Directory services map network resource names to network addresses and create a network name structure. Let's look at network directory services like DNS and LDAP.
DNS (Domain Name System)
The DNS's job is to convert human-readable domain names like ourtechroom.com into IP addresses (like 192.168.10.12) so that the web browser can access the server's resources. If there is no DNS, you must remember the IP address and access the desired sites using the IP address rather than a domain name such as ourtechroom.com.
LDAP (Lightweight Directory Access Protocol)
It is a lightweight client-server directory protocol for accessing directory services. If your data do not change frequently then you can store your data in LDAP Services and you can access it frequently as LDAP provides a ' write-once-read-multiple-times' service, whereas in SQL database you can have high read and writes. So, we can say LDAP is non-transactional.
6) Automatic Network Address Configuration
Giving a unique IP address to all the systems in a network is done by Automatic Network Address Configuration devices like DHCP(Dynamic Host Configuration Protocol)Server.DHCP server's main works are to make sure that no two systems got the same IP address.
Our home router is already pre-configured with the DHCP server and we should not have to worry much about assigning dynamic IP to the computer. Suppose a computer connects to a network then this computer will request an IP address to the router, then in the router, we have a DHCP server, then what DHCP Server does is it looks in a pool of available IP addresses if found then send back to the computer and finally your computer will have IP which is dynamic in nature.
7) Network Management Services
Network management services are also one of the important services of the internet which are helpful for network managers. Network management services help in preventing, monitoring, diagnosing, and solving issues related to the network.
Some common network management tools are traceroute and ping.
ping: ping tool mainly helps to check the availability of the host machine and the time is taken to respond to all Internet Control Message Protocol (ICMP) packets.
Here, we can clearly see, that all request sent by computer reaches to google server with no packet loss. 100% of the request reaches the server and 100% of the response reaches me from the server.
traceroute: traceroute tool mainly helps to find and display all the possible routes(pathways) from request to response and get time taken for responding on each pathway.
We can clearly see that under 11 hops, my request to google.com reaches to google server.
Checking each and every device in a network is tedious so for this we have SNMP, which stands for Simple Network Management Protocol. It is mainly used for network monitoring, and network failure identification among various devices in a network.
9) Time Services
Network Time Protocol (NTP) is a popular time service on the internet that helps to synchronize and set the computer clock with great precision. Computer clocks are synced to either Greenwich Mean Time (GMT) or Co-ordinated University Time (UTC).NTP is the oldest computer protocol currently in use.
Windows Time after Windows 2000 uses an NTP server for synchronization. It is the best software implementation example of Time Service. Windows Time Service(W32Time) is a background service running in your system which provides clock synchronization for the computer to the NTP server. (source).
Other Software Implementations of Time Services are:
- SNTP: SNTP is a time-keeping protocol that allows system clocks (from desktops to servers) to be synchronized by adjusting your computer clock with the servers.
- OpenNTPD: To keep a computer system's clock in sync with a network of NTP servers, the OpenNTPD (also known as OpenBSD NTP Daemon) daemon is used. It can also function as an NTP server for clients that are NTP-compliant.
- NTPsec: NTPsec is a secured form of NTP.
- Ntimed : Ntimed is highly secured and highly performance form of NTP.
Similar other time service protocols are: Daytime Protocol (RFC-867), Time Protocol(RFC-868) (source)
10) Usenet News
Usenet is known as the 'User's Network.' It is one of the oldest networks where users can post files to news servers and other members can access it.
Newsgroups are an active Online Discussion Forum, which can easily be accessed through Usenet. Each newsgroup includes discussions on a particular subject that are implied in the newsgroup name.
E-commerce is Internet-based buying and sale of goods and services. Today, almost anything that is available in the market can be purchased through e-commerce.
Ans: Internet service is most commonly provided by cable, fibre, DSL, and satellite.