What is the Internet?
Large network of computers which communicate all together.
A simple network
In order to communicate, computers are link to each other. We can use ethernet or wifi to connect computers from one another.
computer <-> computer
A link of computers are connected to another link of computers by using routers. Routers are use to send message to another computer and vice versa.
computers <-> routers <-> computers
In order to connect to much more set of computers, routers are link to another routers
computers <-> routers <-> routers <-> computers
Routers are now connected to modems which are connected to telephone infrastructure that will help us to connect to other networks such as our friends, neighbors, etc.
computers <-> routers <-> modem <-> routers <-> computers
ISPs are special routers that are linked together in order for us to communicate to other network such across other countries.
computers <-> routers <-> modem <-> ISP <-> ISP <-> modem <-> routers <-> computers
( ISP is a company that manages some special routers that are all linked together and can also access other ISP's routers.)
- We use IP address (Internet Protocol) to identify the address of a computer. It is a series of four numbers separated by dots.
- We use a domain name so that instead of remembering the IP address, we can remember them by using it on top of the IP address.
Internet and the web
- Internet is an infrastructure. Inter connected computers.
- Web is a service built on top of the infrastructure.
Difference between webpage, website, web server, and search engine?
- A webpage is a document which can be displayed in a web browser such as firefox, google chrome, opera Microsoft edge, Apple Safari, These are also often called just "pages".
Often written in HTML
A website is a collection of web pages which are group together and usually connected together in various ways. Often called a "web site" or a "site".
A web server is a computer that hosts a website on the internet.
- A search engine is a web service that helps you find other web pages, such as Google, Bing, Yahoo, of DuckDuckGo.
Clients and Servers
- Clients are the typical web user's internet-connected devices
- Servers are computers that store webpages, sites, or apps.
- Internet connection allows us to send and retrive data on the web.
- TCP/IP (Transmission Control Protocol and Internet Protocol) are communication protocols that define how data should travel acros the internet.
- DNS (Domain Name System) is like an address book for websites.
- HTTP (Hypertext Transfer Protocol) is an application protocol that defines a language for clients and servers to speak to each other.
- Component Files: a website is made of many different files
- assets: collective stuff such as images, music, video, word documentts and PDFs.