Course: From Basic Science to Web Hosting

Module 01 — Basic Science

Lesson 001 — What Is Technology?

Difficulty: Beginner
Prerequisites: None
Estimated time: 10 minutes

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1. Learning Objectives

After this lesson, you should understand:

• What technology means
• The difference between science and technology
• Why technology depends on physical principles
• How basic science eventually leads to computers
• How computers eventually lead to web hosting

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2. What Is Technology?

Technology is the use of knowledge, scientific principles, tools, materials, and processes to solve problems or accomplish useful tasks.

A simple example is a lamp.

Problem
  ↓
Need light
  ↓
Electrical technology
  ↓
Lamp
  ↓
Light

A modern web server is also technology.

Problem
  ↓
Need to provide information to people
  ↓
Computer
  ↓
Network
  ↓
Web server
  ↓
Website

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3. Science vs Technology

These two ideas are related but different.

Science asks:

How does nature work?

Examples:

Why does electricity flow?
Why do materials conduct electricity?
How does light travel?
How does matter behave?

Technology asks:

How can we use what we know to accomplish something?

For example:

Scientific knowledge
       ↓
Semiconductor physics
       ↓
Transistor
       ↓
Computer chip
       ↓
Computer

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4. Technology Starts With the Physical World

Before a computer existed, there was physical matter.

Matter
 ↓
Atoms
 ↓
Electrons
 ↓
Electricity
 ↓
Electronic devices
 ↓
Transistors
 ↓
Digital circuits
 ↓
Computer

Therefore, a computer isn’t something separate from physics.

A computer is a physical machine that uses physical processes to represent and manipulate information.

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5. What Is a Physical State?

Everything around us can have different states.

For example:

Lamp

OFF
ON

A switch can have:

OPEN
CLOSED

A voltage can have different values.

A transistor can operate in different electrical conditions.

Digital electronics takes advantage of controlled physical states.

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6. From Physical State to Information

Suppose we have a switch:

OFF → 0
ON  → 1

We have now created a simple representation.

The physical state:

OFF / ON

is interpreted as:

0 / 1

This is the beginning of digital information.

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7. From One Bit to Many Bits

One binary state gives us:

0
1

Two binary states give:

00
01
10
11

Eight bits give one byte:

10110010

These patterns can represent:

Numbers
Characters
Instructions
Image data
Audio data
Video data
Network data

The pattern has meaning because we have agreed on how to interpret it.

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8. Information Needs Representation

Consider:

A

A computer cannot directly manipulate the human concept of the letter A.

It uses a representation.

For example:

A
 ↓
65
 ↓
01000001

The computer’s electronic circuits manipulate the binary representation.

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9. Information Needs Processing

Suppose we want:

5 + 3

A computer converts the numbers into representations and uses electronic logic to perform the operation.

Conceptually:

5
 ↓
Binary representation
 ↓
Electronic circuits
 ↓
Addition
 ↓
Result
 ↓
8

This is computation.

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10. Information Needs Storage

If information must remain available after an operation, it needs to be stored.

Examples:

RAM
SSD
Hard disk
Flash memory

Conceptually:

Information
     ↓
Physical state
     ↓
Memory

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11. Information Needs Communication

Suppose one computer needs to send information to another.

Computer A
    ↓
Information
    ↓
Signal
    ↓
Network
    ↓
Signal
    ↓
Computer B

This creates the field of computer networking.

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12. From Computer to Internet

One computer can communicate with another.

Then many computers can connect:

Computer
   ↓
Network
   ↓
Network
   ↓
Network
   ↓
Internet

The Internet is therefore not one giant computer.

It is a network of interconnected networks.

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13. From Internet to Web

The Internet provides the communication infrastructure.

The Web is one of the services built on that infrastructure.

Conceptually:

Internet
   ↓
TCP/IP
   ↓
HTTP
   ↓
Web

A browser can communicate with a web server using HTTP/HTTPS.

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14. From Web to Web Hosting

Now we arrive at your main subject.

Someone wants a website.

The website needs somewhere to run and store its files.

Website files
     ↓
Computer/server
     ↓
Internet connection
     ↓
Web server
     ↓
Visitors

Providing this infrastructure is web hosting.

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15. What Is a Server?

A server is fundamentally a computer that provides a service to other computers.

For example:

Web server
Database server
Mail server
DNS server
File server

A web server provides web content.

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16. Your Hosting Server

Your own hosting environment can be understood as:

Physical infrastructure
        ↓
Cloud infrastructure
        ↓
Virtual Machine
        ↓
Ubuntu Linux
        ↓
Nginx
        ↓
PHP
        ↓
MySQL
        ↓
WordPress
        ↓
Website

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17. The Complete Journey

Now connect everything:

Physics
  ↓
Matter
  ↓
Atoms
  ↓
Electrons
  ↓
Electricity
  ↓
Semiconductors
  ↓
Transistors
  ↓
Digital logic
  ↓
Computer
  ↓
Operating system
  ↓
Networking
  ↓
Internet
  ↓
HTTP
  ↓
Web server
  ↓
Website
  ↓
Web hosting

This is the learning journey we will follow throughout CresignSys Learn.

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18. Important Idea

Don’t think of web hosting as something completely separate from basic science.

It is the top layer of a very large technology stack.

                  WEB HOSTING
                       ↑
                    WEBSITE
                       ↑
                     HTTP
                       ↑
                   NETWORK
                       ↑
                  OPERATING SYSTEM
                       ↑
                    COMPUTER
                       ↑
                  DIGITAL LOGIC
                       ↑
                   TRANSISTOR
                       ↑
                  SEMICONDUCTOR
                       ↑
                   ELECTRICITY
                       ↑
                    PHYSICS

Each layer depends on the layers underneath it.

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19. Practical Thinking

When you eventually execute:

sudo systemctl restart nginx

you are actually interacting with many layers:

Command
 ↓
Shell
 ↓
Linux
 ↓
systemd
 ↓
Nginx process
 ↓
CPU instructions
 ↓
Memory
 ↓
Electronic circuits
 ↓
Physical hardware

This is why learning the fundamentals is valuable.

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20. Summary

Remember these seven ideas:

1. Nature provides physical laws.
2. Science studies those laws.
3. Engineering uses that knowledge.
4. Electronics controls physical signals.
5. Computers use those signals to process information.
6. Networks allow computers to communicate.
7. Web hosting provides computers, software, and connectivity
   for websites and web applications.

The next lesson

Lesson 002 — What Is Matter?

We will go one level deeper:

Matter
 ↓
Atoms
 ↓
Nucleus
 ↓
Protons
 ↓
Neutrons
 ↓
Electrons
 ↓
Electric charge
 ↓
Why electrons matter to computers

That lesson is the proper starting point for understanding electricity → semiconductor → transistor → computer → server → web hosting.