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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Self-Learning Journey by 7vikfox</title>
  <link rel="stylesheet" href="style.css">
</head>
<body>

  <h1>Self-Learning Journey</h1>
  <p>Tracking my progress in IT</p>

  <hr>
  <h3>Links</h3>
<li><a href="cybersecurity.html">🔐 Cybersecurity Notes</a></li>
<li><a href="cloud-devops.html"> ☁⚙ Cloud Computing & DevOps Notes</a></li>
<li><a href="DSA.html"> DSA Notes</a></li>
  <li><a href="codes.html"> Codes Notes</a></li>
<li><a href="projects.html"> Projects Section</a></li>

<h2 id="sql">SQL Notes</h2>

<ul>
  <li><strong>1. View all data</strong><br>
    Used to display every record from a table.
    <pre>
SELECT * FROM students;
    </pre>
  </li>

  <li><strong>2. Insert data</strong><br>
    Adds a new row into a table.
    <pre>
INSERT INTO students (id, name, age, grade)
VALUES (1, 'Alex', 20, 'A');
    </pre>
  </li>

  <li><strong>3. Update data</strong><br>
    Modifies existing records in a table.
    <pre>
UPDATE students
SET grade = 'B'
WHERE name = 'Alex';
    </pre>
  </li>

  <li><strong>4. Delete data</strong><br>
    Removes records from a table.
    <pre>
DELETE FROM students
WHERE name = 'Alex';
    </pre>
  </li>

  <li><strong>5. Filter records (WHERE)</strong><br>
    Retrieves data based on conditions.
    <pre>
SELECT * FROM students
WHERE age &gt; 18;
    </pre>
  </li>

  <li><strong>6. Sort records (ORDER BY)</strong><br>
    Sorts results in ascending or descending order.
    <pre>
SELECT * FROM students
ORDER BY age ASC;
    </pre>
  </li>

  <li><strong>7. Count records</strong><br>
    Returns the total number of rows.
    <pre>
SELECT COUNT(*) AS total_students
FROM students;
    </pre>
  </li>

  <li><strong>8. Average values</strong><br>
    Calculates the average of a numeric column.
    <pre>
SELECT AVG(age) AS average_age
FROM students;
    </pre>
  </li>

  <li><strong>9. Group data</strong><br>
    Groups records and applies aggregate functions.
    <pre>
SELECT grade, COUNT(*) AS total_students
FROM students
GROUP BY grade;
    </pre>
  </li>
</ul>

<hr>

<h2 id="python">Python Notes</h2>
<ul>
  <li>Python is a high-level programming language.</li>
  <li>Supports procedural, object-oriented, and functional programming.</li>
  <li>Basic syntax example:
    <pre>
# This is a comment
print("Hello, World!")
x = 10
if x &gt; 5:
    print("x is greater than 5")
    </pre>
  </li>
  <li><b>input()</b> is used to take user input as text (string):
    <pre>
name = input("Enter your name: ")
print(name)
    </pre>
  </li>
  <li><b>int()</b> converts a string into an integer:
    <pre>
marks = int(input("Enter marks: "))
    </pre>
  </li>
  <li><b>Basic arithmetic</b>: +, -, *, / can be used for calculations:
    <pre>
total = math + science + english + hindi
percent = total / 4
    </pre>
  </li>
  <li><b>f-strings</b> are used for formatted printing:
    <pre>
print(f"Total: {total}")
print(f"Percentage: {percent}%")
    </pre>
  </li>
  <li>Common data types: int, float, str, list, dict, tuple, set</li>
<li><b>Variables</b> are used to store data:
    <pre>
name = "John"
age = 20
    </pre>
  </li>

  <li><b>If-Else Condition</b> is used to check conditions:
    <pre>
age = 18
if age &gt;= 18:
    print("Adult")
else:
    print("Minor")
    </pre>
  </li>

  <li><b>While Loop</b> repeats code until condition becomes false:
    <pre>
while guess != number:
    print("Try again")
    </pre>
  </li>

  <li><b>Random Number</b> using random module:
    <pre>
import random
number = random.randint(1, 10)
    </pre>
  </li>

  <li><b>Programs Learned:</b>
    <ul>
      <li>Greeting Program</li>
      <li>Number Guessing Game</li>
</ul>
</li>

<hr>

<h2 id="java">Java Basics Notes</h2>

<ul>
  <li>
    <b>Java</b> is a high-level, object-oriented programming language
    designed to be platform-independent.
  </li>

  <li>
    <b>Key Features of Java</b>
    <ul>
      <li>Object-Oriented</li>
      <li>Platform Independent (Write Once, Run Anywhere)</li>
      <li>Secure and Robust</li>
      <li>Automatic Memory Management (Garbage Collection)</li>
    </ul>
  </li>

  <li>
    <b>Basic Java Program Structure</b>
    <pre>
class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}
    </pre>
  </li>

  <li>
    <b>Java Data Types</b>
    <ul>
      <li>Primitive: int, float, double, char, boolean</li>
      <li>Non-Primitive: String, Array, Class, Interface</li>
    </ul>
  </li>

  <li>
    <b>Variables</b>
    <pre>
int age = 20;
double price = 99.99;
char grade = 'A';
boolean isActive = true;
    </pre>
  </li>

  <li>
    <b>Conditional Statements</b>
    <pre>
int marks = 75;

if (marks >= 50) {
    System.out.println("Pass");
} else {
    System.out.println("Fail");
}
    </pre>
  </li>

  <li>
    <b>Loops</b>
    <ul>
      <li>For Loop</li>
      <li>While Loop</li>
      <li>Do-While Loop</li>
    </ul>

    <pre>
for (int i = 1; i <= 5; i++) {
    System.out.println(i);
}
    </pre>
  </li>

  <li>
    <b>Methods (Functions)</b>
    <pre>
static void greet() {
    System.out.println("Hello from Java");
}
    </pre>
  </li>

  <li>
    <b>Object-Oriented Concepts (Basics)</b>
    <ul>
      <li>Class</li>
      <li>Object</li>
      <li>Encapsulation</li>
      <li>Inheritance</li>
      <li>Polymorphism</li>
      <li>Abstraction</li>
    </ul>
  </li>
</ul>

<p>
  <b>Next Topics:</b>
  Classes & Objects (deep), Constructors,
  Inheritance, Interfaces, Exception Handling.
</p>

<hr>


  <h2 id="html">HTML Notes</h2>
  <ul>
    <li>HTML stands for HyperText Markup Language.</li>
    <li>Used to structure content on the web.</li>
    <li>Basic elements:
      <pre>
&lt;h1&gt;Heading&lt;/h1&gt;
&lt;p&gt;Paragraph&lt;/p&gt;
&lt;a href="url"&gt;Link&lt;/a&gt;
&lt;ul&gt;&lt;li&gt;List Item&lt;/li&gt;&lt;/ul&gt;
      </pre>
    </li>
    <li>HTML elements have tags and attributes.</li>
  </ul>

  <hr>

  <h2 id="css">CSS Notes</h2>
  <ul>
    <li>CSS stands for Cascading Style Sheets.</li>
    <li>Used to style HTML content: colors, fonts, layout.</li>
    <li>Basic example:
      <pre>
&lt;style&gt;
  body {
    background-color: lightblue;
  }
  h1 {
    color: navy;
  }
&lt;/style&gt;
      </pre>
    </li>
    <li>Selectors target HTML elements to apply styles.</li>
  </ul>

<hr>

<h2 id="operating-system">Operating System (OS) Notes</h2>

<ul>
  <li><b>Operating System (OS)</b> is system software that manages hardware, software, and user interaction.</li>

  <li><b>Main Functions of an OS</b>
    <ul>
      <li>Process management</li>
      <li>Memory management</li>
      <li>File system management</li>
      <li>Device management</li>
      <li>Security and access control</li>
    </ul>
  </li>

  <li><b>Types of Operating Systems</b>
    <ul>
      <li>Batch Operating System</li>
      <li>Time-Sharing Operating System</li>
      <li>Distributed Operating System</li>
      <li>Real-Time Operating System (RTOS)</li>
      <li>Network Operating System</li>
    </ul>
  </li>

  <li><b>Process Management</b>
    <ul>
      <li>A process is a program in execution</li>
      <li>Process States:
        <pre>
New → Ready → Running → Waiting → Terminated
        </pre>
      </li>
      <li>Context Switching – Switching CPU between processes</li>
    </ul>
  </li>

  <li><b>CPU Scheduling Algorithms</b>
    <ul>
      <li>FCFS – First Come First Serve</li>
      <li>SJF – Shortest Job First</li>
      <li>Round Robin</li>
      <li>Priority Scheduling</li>
    </ul>
  </li>

  <li><b>Memory Management</b>
    <ul>
      <li>RAM – Primary memory</li>
      <li>Virtual Memory – Uses disk as extended RAM</li>
      <li>Paging and Segmentation</li>
    </ul>
  </li>

  <li><b>Deadlock</b>
    <ul>
      <li>Occurs when processes wait indefinitely</li>
      <li>Deadlock Conditions:
        <ul>
          <li>Mutual Exclusion</li>
          <li>Hold and Wait</li>
          <li>No Preemption</li>
          <li>Circular Wait</li>
        </ul>
      </li>
    </ul>
  </li>

  <li><b>File System</b>
    <ul>
      <li>Manages data storage and retrieval</li>
      <li>Common file systems:
        <ul>
          <li>NTFS (Windows)</li>
          <li>EXT4 (Linux)</li>
          <li>FAT32</li>
        </ul>
      </li>
    </ul>
  </li>

  <li><b>Security in OS</b>
    <ul>
      <li>User authentication and authorization</li>
      <li>Access control and permissions</li>
      <li>Process isolation</li>
    </ul>
  </li>
</ul>

<p><b>Next Topics:</b> Linux commands, Windows internals, system calls, virtualization, containers.</p>

<hr>

<h2 id="js-ts">JavaScript & TypeScript Notes (Smart Comparison)</h2>

<p>
  <b>JavaScript (JS)</b> and <b>TypeScript (TS)</b> are closely related.
  TypeScript is a <b>superset of JavaScript</b>, meaning:
  <br>
  <i>All JavaScript code is valid TypeScript code.</i>
</p>

<ul>
  <li>
    <b>Main Difference</b>
    <ul>
      <li>JavaScript → Dynamic typing</li>
      <li>TypeScript → Static typing + JavaScript features</li>
    </ul>
  </li>

  <li>
    <b>Basic Variable Declaration</b>

    <pre>
JavaScript:
let age = 25;

TypeScript:
let age: number = 25;
    </pre>
  </li>

  <li>
    <b>Data Types</b>

    <pre>
JavaScript:
let name = "Alex";
let isActive = true;

TypeScript:
let name: string = "Alex";
let isActive: boolean = true;
    </pre>
  </li>

  <li>
    <b>Functions</b>

    <pre>
JavaScript:
function add(a, b) {
    return a + b;
}

TypeScript:
function add(a: number, b: number): number {
    return a + b;
}
    </pre>
  </li>

  <li>
    <b>Arrays</b>

    <pre>
JavaScript:
let numbers = [1, 2, 3];

TypeScript:
let numbers: number[] = [1, 2, 3];
    </pre>
  </li>

  <li>
    <b>Objects</b>

    <pre>
JavaScript:
let user = {
    name: "Sam",
    age: 22
};

TypeScript:
let user: {
    name: string;
    age: number;
} = {
    name: "Sam",
    age: 22
};
    </pre>
  </li>

  <li>
    <b>Why TypeScript Exists</b>
    <ul>
      <li>Catches errors at compile time</li>
      <li>Better code readability</li>
      <li>Great for large applications</li>
      <li>Excellent IDE support</li>
    </ul>
  </li>

  <li>
    <b>Compilation Flow</b>

    <pre>
TypeScript (.ts)
      ↓
Compiled to JavaScript (.js)
      ↓
Runs in Browser / Node.js
    </pre>
  </li>

  <li>
    <b>Where They Are Used</b>
    <ul>
      <li>JavaScript → Browsers, Node.js, web apps</li>
      <li>TypeScript → Angular, React, enterprise apps</li>
    </ul>
  </li>
</ul>

<p>
  <b>Learning Strategy:</b>
  Learn JavaScript fundamentals first, then
  move to TypeScript for safer and scalable code.
</p>

<hr>

<h2 id="networking">Networking Notes</h2>

<ul>
  <li><b>Networking</b> is the practice of connecting computers and devices to share data and resources.</li>

  <li><b>Types of Networks</b>
    <ul>
      <li>LAN (Local Area Network) – Small area like home, office</li>
      <li>MAN (Metropolitan Area Network) – City-wide network</li>
      <li>WAN (Wide Area Network) – Large area like the Internet</li>
    </ul>
  </li>

  <li><b>Basic Networking Devices</b>
    <ul>
      <li>Router – Connects different networks</li>
      <li>Switch – Connects devices within a network</li>
      <li>Modem – Connects network to ISP</li>
      <li>Firewall – Protects network from threats</li>
    </ul>
  </li>

  <li><b>IP Address</b>
    <ul>
      <li>Unique identifier for a device on a network</li>
      <li>IPv4 example:
        <pre>
192.168.1.1
        </pre>
      </li>
      <li>IPv6 example:
        <pre>
2001:0db8:85a3::8a2e:0370:7334
        </pre>
      </li>
    </ul>
  </li>

  <li><b>Common Network Protocols</b>
    <ul>
      <li>HTTP / HTTPS – Web communication</li>
      <li>FTP – File transfer</li>
      <li>SMTP – Sending emails</li>
      <li>IMAP / POP3 – Receiving emails</li>
      <li>DNS – Converts domain names to IP addresses</li>
    </ul>
  </li>

  <li><b>Ports</b>
    <pre>
HTTP  : 80
HTTPS : 443
FTP   : 21
SMTP  : 25
SSH   : 22
    </pre>
  </li>

  <li><b>OSI Model (7 Layers)</b>
    <pre>
7. Application
6. Presentation
5. Session
4. Transport
3. Network
2. Data Link
1. Physical
    </pre>
  </li>

  <li><b>TCP vs UDP</b>
    <ul>
      <li>TCP – Reliable, connection-oriented</li>
      <li>UDP – Faster, connectionless</li>
    </ul>
  </li>
</ul>

<hr>

<h2 id="network-security">Network Security Notes</h2>

<ul>
  <li><b>Network Security</b> refers to protecting networks, devices, and data from unauthorized access, attacks, and misuse.</li>

  <li><b>Goals of Network Security (CIA Triad)</b>
    <ul>
      <li>Confidentiality – Data is accessible only to authorized users</li>
      <li>Integrity – Data is not altered without permission</li>
      <li>Availability – Systems and data are accessible when needed</li>
    </ul>
  </li>

  <li><b>Common Network Threats</b>
    <ul>
      <li>Malware – Viruses, worms, trojans</li>
      <li>Phishing – Fake messages to steal credentials</li>
      <li>Man-in-the-Middle (MITM) – Intercepting communication</li>
      <li>Denial of Service (DoS / DDoS) – Overloading a system</li>
      <li>Packet Sniffing – Capturing network traffic</li>
    </ul>
  </li>

  <li><b>Firewalls</b>
    <ul>
      <li>Filter incoming and outgoing network traffic</li>
      <li>Types:
        <ul>
          <li>Packet-filtering firewall</li>
          <li>Stateful firewall</li>
          <li>Application-level firewall</li>
          <li>Next-Generation Firewall (NGFW)</li>
        </ul>
      </li>
    </ul>
  </li>

  <li><b>Encryption</b>
    <ul>
      <li>Protects data during transmission</li>
      <li>Symmetric Encryption – Same key for encryption & decryption</li>
      <li>Asymmetric Encryption – Public key & private key</li>
      <li>Examples:
        <pre>
HTTPS → TLS/SSL
SSH   → Secure remote access
        </pre>
      </li>
    </ul>
  </li>

  <li><b>Authentication Methods</b>
    <ul>
      <li>Password-based authentication</li>
      <li>Multi-Factor Authentication (MFA)</li>
      <li>Biometric authentication</li>
      <li>Certificate-based authentication</li>
    </ul>
  </li>

  <li><b>IDS & IPS</b>
    <ul>
      <li>IDS (Intrusion Detection System) – Detects attacks</li>
      <li>IPS (Intrusion Prevention System) – Detects and blocks attacks</li>
    </ul>
  </li>

  <li><b>Secure Network Practices</b>
    <ul>
      <li>Use strong passwords and MFA</li>
      <li>Keep systems and software updated</li>
      <li>Segment networks (VLANs)</li>
      <li>Disable unused ports and services</li>
      <li>Monitor logs and traffic</li>
    </ul>
  </li>

  <li><b>Common Secure Ports</b>
    <pre>
HTTPS : 443
SSH   : 22
FTPS  : 990
SFTP  : 22
    </pre>
  </li>
</ul>

<hr>

  <h2>Next Steps</h2>
  <p>Gradually add more notes, code examples, and learning resources for each field.</p>
  <h3>Links</h3>
 <li><a href="cybersecurity.html">🔐 Cybersecurity Notes</a></li>
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