How DNS works: a plain explanationWhat happens when you type a web address? A simple walkthrough of DNS — domain hierarchy, resolvers, caching and TTL.What is a CDN? A plain explanationWhy web pages load fast everywhere: how content delivery networks cache files at the edge, route visitors to the nearest server, and protect sites from attacks.How email works: SMTP, IMAP and POP3 explainedWhat happens between pressing send and the message arriving — servers, protocols, and why IMAP beat POP3.What is a firewall? Types and how they workA plain explanation of firewalls — what they filter, the main types, and what they cannot protect.How HTTPS works: the lock icon explainedWhat actually happens when you see the padlock? Encryption, certificates and why every website should use HTTPS.IP addresses: IPv4 vs IPv6 explainedWhat an IP address is, why IPv4 ran out, and how IPv6 fixes it — including shorthand and practical differences.What is a proxy server and how does it work?A plain explanation of proxy servers — forward vs reverse, what they do, the headers they add, and what they cannot protect.TCP vs UDP: what's the difference?TCP and UDP are the two main ways data travels over the internet. TCP is reliable but slower; UDP is fast but lossy. Here's when each one is used.What is a VPN and how does it work?A plain explanation of VPNs — encryption, tunneling, what they protect, and what they don't.How Wi-Fi works: a plain explanationRadio waves, access points, bands and security — how Wi-Fi actually delivers internet to your devices.What is HTTP/3? A plain explanationThe newest version of HTTP runs on QUIC, a transport built on UDP instead of TCP. Here's what changes — and why pages feel faster with it.What are WebSockets? A plain explanationWebSockets keep a two-way connection between browser and server open, so either side can send data any time. Here's how the handshake, frames, and close codes work — and when to use them.OSI model explained: the 7 layers of networkingThe OSI model explained: what the 7 layers (physical to application) do, how data moves through them, and how the model compares with the real TCP/IP stack.SSH explained: how Secure Shell worksSSH explained: what Secure Shell is, how the protocol works end to end, and why it replaced telnet and rsh.What is SSRF (Server-Side Request Forgery)? How it works and how to prevent itServer-Side Request Forgery (SSRF) lets an attacker abuse a server's own URL-fetching feature to reach internal systems and cloud metadata. This guide explains the attack and the defenses that stop it.What is an API Gateway? A practical guide for developersAn API gateway is a single front door for all client requests to your back-end services. This guide explains what an API gateway does, the problems it solves, common patterns, and how to choose one.How to configure DNS records: A, AAAA, CNAME, MX, and TXT explainedConfigure DNS records for your domain: learn what A, AAAA, CNAME, MX, and TXT records do, when to use each, and how to verify your changes propagate correctly.What is HSTS (HTTP Strict Transport Security)? How it works and why it mattersHTTP Strict Transport Security (HSTS) is a web security policy that forces browsers to only use HTTPS. Learn how the Strict-Transport-Security header works, what it protects against, and how HSTS preload lists eliminate the SSL-stripping window.What is load balancing? How load balancers work and key algorithmsLoad balancing is the process of distributing incoming traffic across multiple servers so that no single server is overloaded. A load balancer sits in front of a pool of servers and decides where to send each request, trading total capacity for reliability and speed. This guide explains how load balancers work, the difference between Layer 4 and Layer 7, the main routing algorithms, and how to choose one.How to set up a reverse proxy with Nginx: a practical guideA reverse proxy sits in front of your web servers and forwards client requests to them. This guide shows you exactly how to set one up with Nginx — proxy_pass, headers, load balancing, TLS and common pitfalls.What is Edge Computing? How it works and when to use itEdge computing moves computation closer to users, reducing latency and bandwidth compared to centralized cloud. This guide explains how it works, its benefits, challenges, and how it compares to traditional cloud computing. 