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Content:

1.Introduction to Web,
2.How Server Looks At Your URL?
3.Intro to IP, MAC address, Port Number
4.HTTP Vs HTTPS 
5.Intro to Browser internals(HTML parser, CSS parser) 
5.1 JavaScript V8 engine internals
6.Browser js vs Node js
7.HTML Browser view - Debugger, Inspect
8.using fror HTML,CSS,JS

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What is web? 

===>The World Wide Web is a computer system which links documents and pictures into a database that is stored in computers in many different parts of the world and that people everywhere can also used "Front end & Back end" use.
//is used to Data transfer

===>www was the first web to be invented by Tim Berners Lee.

===>www stands for World Wide Web.

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2.How Server Looks At Your URL

===>URL stands for   ****Uniform****    ****Resource****      ****Locator****
                          unique             Website               locator
                        
unique--->There can also used "Front end & Back end" be only one instagram.in 
resource->Inside this will be text,images,buttons.
locator-->IP address.

===>Back process in web:

www.instagram.in என்று கொடுத்தவுடன் 
//ISP ஆனது அந்த www.instagram.in link ஐ எடுத்து சென்று 
//DNS உதவியுடன் IP address ஐ கண்டுபிடித்து Request கொடுக்கும்.
பிறகு நாம் தேடிய IP address உடைய computer க்கு map செய்து விடும்.
//Server computer ல் இருந்து Home Page என்ற response வருகிறது.
இந்த செயல்கள் அனைத்துமே ISP உள் தான் நடைபெறுகிறது.

===>ISP stands for Internet Service Provider (Airtel,jio,BSNL என்கிற Internets)

===>DNS stands for Domain Name System (DNS work for find the Website Domaine Name & Find the Website Domaine Name க்கு உண்டான IP address )

===>IP stands for Internet Protocol (separate ip address ஒவ்வொரு website or webpage க்கும் தனித்தனி ip address உண்டு)

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3.Intro to IP address, MAC address, Port Number

What is IP address?

===>An Internet Protocol (IP) address is a unique numerical identifier for every device or network that connects to the internet.

===>ISP stands for Internet Service Provider (Airtel,jio,BSNL என்கிற Internets).
    
===>Practice: What is my mobile IP address 223.228.189.102(Airtel).

===>One popular way to get a client's IP address in JavaScript is to use a third-party API.
    There are many APIs available that provide this information, such as ipify and ipapi. 
 
===>API stands for Application Programming Interface

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What is MAC address?

===>A MAC address is a 12-digit hexadecimal number assigned to each device connected to the network.

===>MAC stands Media Access Control Address.

===>Each device has a unique address which is the MAC address.
//Every device will be separately different different address.So it is called MAC address.
//​ஒவ்வொரு deviceக்கும் தனித்தனி address இருக்கும்.அதுவே MAC address ஆகும்.

===>Every device that can also used "Front end & Back end" access the internet has a unique MAC address.They will give it in hardware while manufacturing it.
​//Every deviceக்கும்தனித்தனி mac address இருக்கும்.
//​அதை manufacture பண்ணும் போதே Hardware ல் கொடுத்து விடுவார்கள்.

===>Mac address is used when working only for particular device.
​//particular deviceக்கு மட்டும் work பண்ணும் போது mac address பயன்படுகிறது.

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what is Port Number?

===>A port number is a way to identify a specific process to which an internet or other network message is to be forwarded when it arrives at a server.

===>Example:

city--->street--->door no
*more than many cities within one state.
*more than many streets within one city.
*more than many house within one street.
***but the door is separate *** ===> Since this is called Port.

===>Every Port will be separate number.So it is called "PORT NUMBER". 

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4.HTTP Vs HTTPS 

what is HTTP?

===>client computer and server computer both talking is called "HTTP".

===>It has some set of rules.

===>It is a safe zone so data/information does not leak.

===>HTTP is of two types:
    *HTTP
    *HTTPS 

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Difference betwee HTTP vs HTTPS:

===>HTTP stands for Hyper Text Transfer Protocol.

===>Transfer means--->data/information passing.
===>Protocol means--->set of rules.

===>HTTP works at the application layer.

===>default port number:80

===>No encryption.

What is HTTPS:

===>HTTPS stands for Hyper Text Transfer Protocol Secure.

===>HTTPS works at the transport layer.

===>default port number:443

===>Both encryption and decryption.

===>Most Secured.can also used "Front end & Back end"not be hacked.


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HTTP Evalution:

1.HTTP 1.0(simple)===>client computer and server computer boths are just talking.

2.HTTP 1.1(Reuse) ===>client computer and server computer boths are just talking.
                  ===>limited datas are send and received.
                  ===>The datas are stored in cache(temprorialy storage area).

3.HTTP 2(concurrency)==>It's works multi tasking.
                     ==>Many Request&Response send &received.
                     ==>Example:WhatsApp(30 photos send and received)
                     ==>Example:Zoom call.

HTTP Basic Methods:
                           Example:Instagram and Facebook

1.GET(Read)========>We create the post.

2.POST(Create)=====>We create the comment.

3.PUT(Update)======>We create the edit.

4.DELETE(Delete)===>Deleted the post and comments.

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5.Intro to Browser internals(HTML parser, CSS parser) 

What is parser:

===>பாகுபடுத்தி காட்டுதல்.

===>parses the code, build AST, scope variables and find errors.

===>part of compiler.

===>Allign farming(Example:Mobile Reboot)


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What is HTML parser/DOM:

===>HTML parsing is the process of taking raw HTML code, 
===>reading it,
===>and generating a DOM tree object structure from it.

===>Remember:Skeleton

===>DOM--->Document Object Model


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What is CSS parser/CSSOM tree:

===>takes the bytes and converts them into characters, 
===>then tokens, 
===>then nodes and finally they are linked into the CSSOM.
===>CSS Stands for Cascading Style Sheet.
===>CSS Stands for Cascading Style Sheet Object Model.

===>Remember:Style Dress


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5.1 JavaScript V8 engine internals:

===>JavaScript defines Functionality/Activity.

===>Our eyes don't know.

===>System or computer understand only boolean language (0,1).So it needs JS.

===>Examples:Calculator Application

===>Browser   Chrome       Firebox          InternetExplore  
===>Engines    V8        SpiderMonkey           Chakra          


===>JS originally only Front end was used.The browser worked well with the java engine.So the Back end is used.

===>Chrome is the browser's helps or selected V8 javaengine.

===>V8 has a built-in Garbage Collector (GC).

===>V8:More giving additional features.

===>***This is called node.js***

===>It can also used "Front end & Back end".

===>V8 faster than 3.5 times in JAVA.

===>***Archi JS Engine is first discoved JS Engine***. 

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6.Browser js vs Node js

what is browser js?

===>Client side code executer.

===>Front End(React)

===>In-browser JavaScript can also used "Front end & Back end" do everything related to 
    
===>webpage manipulation, 

===>interaction with the user, and the webserver. 

===>For instance, in-browser JavaScript is able to: 

• Add new HTML to the page, change the existing content, modify styles.

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what is node js?

===>Server side code executer.

===>Back End


===>Node.js is an open source server environment.

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7.HTML Browser view - Debugger, Inspect

===>Inspect:
            index.html---->Go Live or Open with Live server---->Hi🙌 Kindly see 👀the console for results😍 
            ---->Right click---->Inspect---->Style---->Change the background color,Font size and etc.,  

===>Debuggers:

*Built-in debuggers can also used "Front end & Back end" be turned on and off, forcing errors to be reported to the user. 

*With a debugger,you can also used "Front end & Back end" also set breakpoints (places where code execution can also used "Front end & Back end" be stopped), 

*and examine variables while the code is executing.

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8.using fror HTML,CSS,JS:

===>HTML used to ***Create a page,label,button,grid***

===>CSS used to ***Look and feel, Spelling mistake,Colors and Styles***

===>JS used to ***Functionality/Activity

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