<DAY-2> Web Dev | Love Babbar’s Course
This is the second blog in Love Babbar’s Web Development course series. Here we will discuss the overview of the network, internet, and client-server model. The topics which were given in homework are also mentioned but I would recommend you to research on your own for once and use this for reference purposes only.
Table of Contents
- Network
- Types of Network- LAN, MAN, WAN (HW)
- IP Address
- Browser
- Browser Engine (HW)
- Client Server Model
- DNS Server
Network
A network in general is an interconnection of entities. A computer network thus is a collection of various devices which are connected via wire or wirelessly to establish a communication medium.
These devices are called end devices and their examples include mobile phones, laptops, PCs, printers, etc. End devices can be any device that is capable of giving or using services.
Types of Network
There are many types of networks based on the range of distance they can cover. We will discuss the three main types — LAN, MAN, and WAN.
LAN
LAN stands for Local Area Network. From the name ‘Local’ we get the idea that it is a network that can cover end devices located ‘locally’ (in the near distance). The internet service we use today via our wifi is a LAN. Our mobiles and laptops are the end devices.
LAN covers the range of roughly up to 2kms. A LAN is established using a Switch and Routers are also found at the end of the network (in the case of internet connectivity.) LANs are easy to set up and provide fast transmission rates. (Switch and Routers are network devices).
MAN
MAN is Metropolitan Area Network. It is a network that connects different cities. The range of MAN is between 5–50km. MAN forms the network by connecting different LANs. An example of MAN is Internet Service Provider.
It can be expensive to set up and tough to maintain. Its transmission speed is moderate.
WAN
WAN or Wide Area Network has a range of above 50 km and is extensible enough to cover the globe. It stands for Wide Area Network. Satellite communication or the Internet can be understood as an example of WAN. Its transmission speed is low.
Internet
We use the internet in our day-to-day life. Let’s consider a scenario. You have to send a photo of yourself to your friends. Some of your friends live in the same city as you, some in other states, and some out of the country. There are various ways in which you can complete your task — by using messaging apps like WhatsApp, Telegram, etc., or by mail. Observe that you are successfully able to send media to all the recipients despite the distance between them or the medium you choose. In our case, WhatsApp or Mail is a Web, and their superset- the network of which they are part is the Internet.
Internet thus simply is a network of networks. It is a global system of networks. The Internet is used to share and receive data across the world. But how does it identify whom to send data from so many end devices? Let’s see.
IP Address
Whenever we send some data, the address of the receiver is sent along with it so that it can reach its correct recipient. An IP address is used to uniquely identify a device over the Internet. It stands for Internet Protocol Address. Not going deep into computer networks, we can understand that it is the duty of internet protocol to send the receiver’s address along with the data.
Browser
A browser (web browser) is a tool that enables us to access resources on the web. It acts as a middleman between the user and World Wide Web. Now you must think why there is a need for an intermediate entity. Why can’t we access the web directly? That is because web pages are created using technologies like HTML, CSS, etc., which need to be interpreted so that the content is displayed correctly.
Examples of browsers include Google Chrome, Safari, Mozilla Firefox, etc. The browser also allows us to navigate through the pages, bookmark sites, etc.
Browser Engine
A browser engine is a component of the web browser that does the rendering (interpretation of code) of web pages. It translates the code and displays the visuals created using the code on the user’s screen. A browser is a complete software whereas the browser engine is a technology used in a browser to process the web content.
Examples include Blink, WebKit, Gecko, EdgeHTML, etc.
Client Server Model
In a network, the device which needs the service is called a client and the device which provides the service is called a server.
The main purpose of a computer network is - transfer of data ( or resources) which is done by a process of request and response. A client-server model makes a partition between the two entities involved in sharing data. The Client generates the request and the server fulfills the request by generating a response.
The types of requests are:
- Get: It is the request to fetch data.
- Post: It is the request to create or submit data.
- Put: It is the request to update data.
- Delete: It is the request to remove data.
DNS Server
Whenever a request is generated the IP address of the server is attached to it in order to identify the server correctly. The IP address looks something like this 142.250.183.78 (IPv4) and 2404:6800:4009:822::200e(IPv6). These are the IP addresses of google.com. IPv4 and IPv6 are just versions of IP addresses that we will discuss later.
So looking at this IP address, we can understand that it is not possible for humans to remember each and every IP address. Therefore a Domain Name System server (DNS server) is used for the interconversion of the domain name and the IP address associated with it.
Outro
I hope you will be able to understand the basic concepts of these topics, again I would like to mention that do research the homework on your own too.
Read previous: https://medium.com/@khushi_koshta/day-1-web-dev-love-babbars-course-f4c57fa67bf9
