How the internet works
A network is made up of at least two devices that connect and communicate via a wired or wireless connection. As the number of computers increase in a network → Network switch: Connects to devices so they communicate with each other effectively. Network switch can connect to other network switches so multiple networks can connect to each other. So many connected network switches → Interconnected network = Internet
- a Service provided on a computer which is called server
- Our device = Client
- ⇒ Client Server Model
What is a web server and how does it work?
Server
Computer that runs applications and services. Called Server because it provides services to other computers(clients)
They are typically stored in data centers, with hundreds or thousands of other servers Why?
- Continuous Power
- Continuous Internet connection
- Server availability 25h per day
Data centers are all around the world to access services as quick as possible Servers are built according to the function required:
- Needs to store a lot of data → the server has a disk with high capacity
- Needs to do complex calculations → has powerful processor
- …
these are the server hardware = they physical component of a server code running on hardware = software
NOTE
Hardware is hard to change as it needs to physically change things Software on the other hand is easy to change
Web Server:
- Website storage and administration
- Data storage
- Security
- Managing emails
- Web request → request respond cycle
What are websites and webpages?
Webpage
A document that shows:
- Images
- Text
- Videos
- Various content in a web browser
Website
is a collection of webpages that link together
HTML, CSS, Java Script:
HTML: Structures the content to be seen CSS: Controls the colors and style Java Script: For user interaction
HTML
Hyper Text Markup Language Works with markup tags. These tags describe the content that should be displayed
CSS
Tells HTML how the content should be displayed and controlling the look and style
Java Script
A programming language that is built into the browser. Data processing, interaction, …
Each line of these codes are processed in a sequential order from first to last. The browser uses the interpreted code and builds the blocks. This process is called Page Rendering.
What is a web browser and how does it work?
Web browser
Sends a request to a web server and receives response from the web server, containing the data that needs to be displayed.
The address of a website = Uniform Resource Locator = URL The URL contains these:
- Protocol
- Domain name
- File name
Browser and web server communicate using HTTP protocol = Hypertext Transfer Protocol This exchange of information is made possible by Request Response Cycle.
Web hosting
If you want to make a website yourself, you have to have a specialized server in a data center? → NO → Web hosting
Web hosting
A service you put your website files in it. It’s a company’s web server. You rent it to have stable and secure storage.
Different types of web hosting
- Shared Hosting
- Virtual Private Hosting
- Dedicated Hosting
- Cloud Hosting
Shared Hosting
The cheapest one. Renting a part of a web server which has multiple websites running. All of them are sharing Processing, bandwidth, and memory resources.
NOTE
Other Website’s performance can have impact on yours.
- Small websites
- Practice
VPS Hosting
VPS = Virtual Private Server A virtual server with dedicated resources along other virtual server instances on a hardware server.
NOTE
Since the resources are fixed, the performance of other instances does not affect yours.
Dedicated Hosting
A hardware server dedicated to you only.
Cloud Hosting
Your website runs on Cloud Environment, which spans across multiple physical and virtual servers. If a server fails, your website will be still online.
- No limitations
- Payed based on used resources. (e.g. paying n cents per megabyte)
- Scalable
Additional Resources
Learn more Here is a list of resources that may be helpful as you continue your learning journey.
What is a Web Server? (NGINX)
https://www.nginx.com/resources/glossary/web-server/
What is a Web Browser? (Mozilla)
https://www.mozilla.org/en-US/firefox/browsers/what-is-a-browser/
Who invented the Internet? And why? (Kurzgesagt)
What is Cloud Computing? (Amazon)
Browser Engines (Wikipedia)
https://en.wikipedia.org/wiki/Browser_engine
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