Week 5: Web Development | Notion

Internet Recap

All the computers on the internet are interconnected that support HTTP and TCP/IP
The internet is an infrastructure to get data from a server to a client
- Supports emails, video conferencing, etc.
The web is one specific application or service that runs atop the internet
- Assumes an internet exists to get data from point A to point B
  - Layers functionality that allows us to click, browse, etc.

Web Browser

Web browsers are found on phones, computers, and game consoles
They have a space to enter a URL (Uniform Resource Locator)
- Prefixed by http:// or https://
When typing in a URL, you’re sending a request from your device to some remote server
- The server looks at your request and figures out how to respond
- Like when we previously requested cat images!

Web Server

A computer that has a CPU, RAM, and a hard drive
Rack servers
- Sized so they can be stacked
Odds are your company has many of these if they have a web server

HTTP

We send requests to web servers
- The language of these requests is HTTP (Hypertext Transfer Protocol)
Request: GET /cat.jpg HTTP/1.1
- 1.1 refers to HTTP language 1.1
Response by the server: HTTP/1.1 200 OK
- This means that everything was okay with the request

HTTP Status Codes

Code	Status	Meaning
200	OK	Everything is OK
301	Moved Permanently	The browser should redirect to a new location
302	Found	The browser should redirect to a new location
304	Not Modified	The browser will cache files if things don’t change to save time/bytes from requests
401	Unauthorized	Not authorized to view content; Could require login
403	Forbidden	Not able to view content
404	Not Found	The requested data could not be found because it doesn’t exist on the server
500	Internal Service Error	Not your fault; The server erred

HTML

In addition to the HTTP headers that include status codes, the bits representing an image or website will be sent to you