Intro to Web Dev: History of the Internet

• The college of Engineering and Information Technology created this introduction to web development

Short History of the Internet

• Early methods for sending messages quickly included radio, telegraph, and telephone
• A telegraph is a device for transmitting and receiving messages over long distances
• Old telephone networks routed calls through operators that physically connected the caller and receiver using wires and a switchboard to complete the circuit
• One drawback of physical connections is the need to establish and maintain a dedicated circuit for the call which is sometimes known as circuit switching
• Circuit switching can make it difficult to have multiple conversations simulatenously, or for computers
• It requires more bandwidth because silences also get transmitted
• ARPANET was created in the 1960's
• ARPANET used packet switching instead of circuit switching

Packet Switching

• Packet switching involves breaking messages into numbered packets
• Each packet can travel a different route
• At the destination, packets are reassembled from packets
• After ARPANET, alternative networks were created, like X.25 in 1974 and USENET built in 1979
• To unify the disparate networks, a suite of protocols was invented
• A protocol is the name given a formal set of publicly available rules to manage data exchange
• Communication protocols let computers communicate, as long as they implement the same procotol
• By 1981, Internet protocols were published and ready for use
• New networks in the US began adopting the Transmission Control Protocol/Internet Protocol (TCP/IP) communication model
• On January 1, 1983, TCP/IP was adopted across all of ARPANET
• Over the next two decades, TCP/IP networking was adopted across the globe

The Birth of the Web

• The world wide web, or WWW, is only a subset of the Internet
• Email and text-based systems were dominant in the late 1980s/early 1990s
• Sir Tim Berners-Lee is the Founding Director of the World Wide Web foundation
• Essential elements of the early web include:
  • A Uniform Resource Locator (URL) to uniquely identify a resource on the WWW
  • The Hypertext Transfer Protocol (HTTP) to describe request and response operations
  • Software (later called web server software) that can respond to HTTP requests
  • Hypertext Markup Language (HTML) to publish documents
  • Software (later called a browser) that can make HTTP requests to URLs and display the HTML it receives

Timeline of the Web

• NCSA Mosaic was released in 1993 by Eric Bina and Marc Andreessen
• Netscape Navigator cofounded by Marc Andreessen was Released in late 1994
• Microsoft released internet explorer in 1995 and it became the market leader
• In late 1994, Berners-Lee helped found the World Wide Web Consortium, or W3C
• W3C is the international standards organization that overseas the growth of the web

Intranet and Internet

• An intranet refers to an internal network using Internet protocols that is local to an organsization
• Intranet resources are often private
• It uses internet protocols like TCP/IP, and is accessible via a web browser

Static Website versus Dynamic Website

• A Static website consists of HTML pages that always look identical for all users
• Users can read a static page, but cannot provide feedback
• A dynamic server-side website:
  • can read content from databases
  • can interface with existing enterprise computer systems
  • communicate with financial institutions
  • outputs HTML that is sent to users' browsers
• In 2006, uploading code might have only taken 12 lines of PHP code
• By 2020, web applications had evolved to use processes such as RabbitMQ or authentication APIs

The Client-Server Model

• A server is a computer agent active 24/7, listening for requests from clients
• A client is a computer agent that makes request and receives responses from the server
• The request-response loop is the most basic mechanism on the server for receiving requests/transmitting data
• A client initiates a request to a server and receives a response that includes a resource like an HTML file, image, or data

The Peer-To-Peer Model

• Each computer is functionally identical
• Each node can send and receive data directly with one another
• Each peer acts as both a client and a server
• Video chat is an example of the peer-to-peer model

Server types

• A web server is a computer servicing HTTP requests
• An application server hosts and executes web applications
• A database server devoted to running a Database Management System, or DBMS, such as MySQL
• A mail server creates and satisfies mail requests, using Simple Mail Transfer Protocol (SMTP)
• A media/streaming server is dedicated to servicing requests for images and videos
• Authentication servers handle the most common security needs of web applications

Real-World Installations

• The goal behind server farms is to distribute incoming requests between machine clusters
• Load balancers distribute requests to available machines
• A typical server farm contains server racks, each containing many servers
• Server farms are typically housed in data centers
• Data centers contain computers/hard drives, air conditioning, redundant power systems, fire suppression systems, and security personnel
• To prevent downtime, large websites exists in mirrored data centers globally

Where Is the Internet?

• The broadband modem (cable or DSL modem) bridges the network hardware outside the house and network hardware inside the house
• The fewer router hops, the quicker the repsonse
• In the 2000s more networks began interconnecting with each other using Internet exchange points, or IX or IXP
• IXPs allow ISPs to peer/interconnect with one another, thereby improving performance
• International Internet communication travels underwater through undersea fiber optic cables
• Satellite internet is used in locations not serviced by undersea cables

Working in Web Development

• Job titles include:
  • Hardware Architect/Network Architect/Systems Engineer
  • System Administrator
  • Database Administrator/Data Architect
  • Security Specialist/Consultant/Expert
  • Developer/Programmer
  • Font-End Developer/UX Developer
  • Software Engineer
  • UX Designer/UI Designer/Information Architect
  • Tester/Quality Assurance
  • Search engine optimization (SEO) Specialist
  • Content Strategists/Marketing Technologist
  • Project Manager/Product Manager
  • Business Analyst
• There are technically nontechnical roles as well

Types of Web Development Companies

• Include:
  • Hosting Companies
  • Design Companies
  • Website Solution Companies
  • Start-Up Companies
  • Intrernal Web Development
  • Vertically integrated companies