Introduction to System  Design

System Design Fundamentals

Introduction to Load  Balancing

Load Balancing Algorithms

Uses of Load Balancing

Load Balancer Types

Stateless vs. Stateful Load Balancing

High Availability and Fault Tolerance

Scalability and Performance

Challenges of Load Balancers

Load Balancing

Introduction to API Gateway

Usage of API gateway

Advantages and disadvantages of using API gateway

API Gateway

Scalability

Availability

Latency and Performance

Concurrency and Coordination

Monitoring and Observability

Resilience and Error Handling

Fault Tolerance vs. High Availability

Key Characteristics of Distributed Systems

HTTP vs. HTTPS

TCP vs. UDP

URL vs. URI vs. URN

Network Essentials

Introduction to DNS

DNS Resolution Process

DNS Load Balancing and High Availability

Domain Name System (DNS)

Introduction to Caching

Why is Caching Important?

Types of Caching

Cache Replacement Policies

Cache Invalidation

Cache Read Strategies

Cache Coherence and Consistency Models

Caching Challenges

Cache Performance Metrics

Caching

What is CDN?

Origin Server vs. Edge Server

CDN Architecture

Push CDN vs. Pull CDN

Introduction to Data Partitioning

Partitioning Methods

Data Sharding Techniques

Benefits of Data Partitioning

Common Problems Associated with Data Partitioning

Data Partitioning

What is a Proxy Server?

Uses of Proxies

VPN vs. Proxy Server

Proxies

What is Redundancy?

What is Replication?

Replication Methods

Data Backup vs. Disaster Recovery

Redundancy and Replication

Introduction to CAP Theorem

Components of CAP Theorem

Trade-offs in Distributed Systems

Examples of CAP Theorem in Practice

Beyond CAP Theorem

CAP & PACELC Theorems

Introduction to Databases

SQL Databases

NoSQL Databases

SQL vs. NoSQL

ACID vs BASE Properties

Real-World Examples and Case Studies

SQL Normalization and Denormalization

In-Memory Database vs. On-Disk Database

Data Replication vs. Data Mirroring

Database Federation

Databases (SQL vs. NoSQL)

What are Indexes?

Types of Indexes

Indexes

Introduction to Bloom Filters

How Bloom Filters Work

Benefits & Limitations of Bloom Filters

Variants and Extensions of Bloom Filters

Applications of Bloom Filters

Bloom Filters

Difference Between Long-Polling, WebSockets, and Server-Sent Events

Long-Polling vs. WebSockets vs. Server-Sent Events

What is Quorum?

Quorum 

What is Heartbeat?

Heartbeat

What is Checksum?

Uses of Checksum

Checksum 

What is Leader and Follower Pattern?

Leader and Follower

What is Security and Privacy?

What is Authentication?

What is Authorization?

Authentication vs. Authorization

OAuth vs. JWT for Authentication

What is Encryption?

What are DDoS Attacks?

Security

Introduction to Messaging System

Introduction to Kafka

Messaging patterns

Popular Messaging Queue Systems

RabbitMQ vs. Kafka vs. ActiveMQ

Distributed Messaging System

What is a Distributed File System?

Architecture of a Distributed File System

Key Components of a DFS

Distributed File Systems

Batch Processing vs. Stream Processing

XML vs. JSON

Synchronous vs. Asynchronous Communication

Push vs. Pull Notification Systems

Microservices vs. Serverless Architecture

Message Queues vs. Service Bus

Stateful vs. Stateless Architecture

Event-Driven vs. Polling Architecture

Misc Concepts

Quiz

Final Quiz

Grokking System Design Fundamentals

VPN (Virtual Private Network) and Proxy Servers are both tools used for privacy and security online, but they function differently and serve distinct purposes. Understanding their differences is essential in determining which one to use based on your needs.

## VPN (Virtual Private Network)

### Definition
- A **VPN** creates a secure, encrypted tunnel between your device and a remote server operated by the VPN service. All your internet traffic is routed through this tunnel, meaning that your data is secure from external observation.

