📖 Full detailed notes here: Open in Notion
The Internet is a global network of interconnected computers that communicate through standardized protocols. It enables worldwide access to information, communication, and services. The foundation of the Internet relies on packet switching technology and the TCP/IP protocol suite to transmit data between devices across diverse networks.
An IP (Internet Protocol) address is a unique numerical identifier assigned to each device connected to a network. IPv4 addresses consist of four octets (e.g., 192.168.1.1), while IPv6 uses a longer hexadecimal format to accommodate more devices. IP addresses enable network devices to locate and identify each other, facilitating routing of data packets across the Internet through both public and private address spaces.
The Domain Name System is a hierarchical decentralized naming system that translates human-readable domain names (like www.example.com) into machine-readable IP addresses. DNS functions as the Internet's phonebook, resolving queries through a global network of servers. This system includes root servers, TLD (Top-Level Domain) servers, and authoritative name servers, working together to provide efficient domain resolution while caching results to improve performance.
Networking fundamentals include understanding how data is transmitted between devices using protocols, packets, and various network architectures. Key concepts encompass the OSI and TCP/IP models, which define networking in layers from physical connections to application data. Other essential elements include bandwidth, latency, routing, switching, firewalls, and network topologies that determine how devices interconnect and communicate across local and wide area networks.
A Local Area Network (LAN) connects devices within a limited geographical area like a home, office, or building, typically using Ethernet or Wi-Fi. Routers are networking devices that forward data packets between different networks, acting as gateways between LANs and wider networks like the Internet. They use routing tables and protocols to determine the optimal path for data transmission, provide network address translation (NAT), and often include firewall functionality for security.
A Virtual Private Network extends a private network across a public network, enabling users to send and receive data as if their devices were directly connected to the private network. VPNs use encryption protocols to create secure tunnels for data transmission, protecting privacy and enhancing security. They provide remote access to network resources, bypass geographical restrictions, and shield browsing activity from surveillance on public networks.
The MERN stack is a popular JavaScript-based web development framework consisting of four technologies: MongoDB (a NoSQL document database), Express.js (a back-end web application framework), React (a front-end JavaScript library for building user interfaces), and Node.js (a JavaScript runtime environment). This full-stack solution allows developers to build dynamic web applications using JavaScript throughout the entire development process, from client-side to server-side and database.
💻 Sample Code and Practice Questions: View on GitHub
💻 Blog Article: View on GitHub