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 an API? A plain-language guide to how APIs workWhat an API is, how REST APIs work over HTTP, the methods you'll actually meet — GET, POST, PUT, PATCH, DELETE — and how to read a response.What is a browser cache? How it speeds up websitesWhere your browser stores copies of images, scripts and fonts, why cached pages load faster, and how to clear the cache or force a fresh copy.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 browser cookies work: a plain guideWhat cookies are, how session and tracking cookies differ, and what 'accept all cookies' actually means.Domain name vs hosting: what's the difference?An address versus a house — what a domain name is, what hosting is, and why you need both for a website.HTTP status codes explained: every code you'll actually seeWhat HTTP status codes mean, grouped by class — 1xx to 5xx — with the codes you'll meet in browsers, APIs, and server logs.HTTP vs HTTPS: what's the difference?The practical differences between HTTP and HTTPS — security, performance, SEO — explained simply.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.What is a URL? The anatomy of a web addressEvery web address is built from a few parts: scheme, domain, path, query and anchor. A plain breakdown of what each one does.What is the World Wide Web? How it's different from the internetThe web and the internet are not the same thing. A plain look at what each is, and how they fit together.HTTP request methods explained: GET, POST, PUT, DELETE & moreWhat HTTP request methods are, what each one does, and the difference between GET, POST, PUT, PATCH, DELETE and the rest — with safe vs idempotent.localStorage vs sessionStorage vs cookies: which one to use?The practical differences between localStorage, sessionStorage and cookies — capacity, lifetime, security and when to pick each one.What is caching? Browser, CDN, server, and database caching explainedHow caching works at every layer of the web — browser cache, CDN edge cache, server-side cache, and database cache — and when each one matters for speed and scalability.REST API design best practices: resource naming, HTTP methods, and status codesHow to design a clean REST API: plural resource URLs, safe and idempotent HTTP methods, meaningful status codes, pagination, and error responses — with practical examples.What is authentication? Passwords, biometrics, SSO, and modern methods explainedAuthentication is the process of verifying who you are. Learn how passwords, multi-factor authentication, biometrics, SSO, OAuth, and password managers work — and which methods offer the best protection for your application.What is code splitting? How it works and when to use itCode splitting divides a JavaScript bundle into smaller chunks that load on demand, speeding up initial page load. This guide explains the technique, the tools, and when it matters most.What is CSRF (Cross-Site Request Forgery)? How it works and how to prevent itCross-Site Request Forgery (CSRF) tricks a logged-in browser into sending unwanted requests to a trusted site. This guide explains how the attack works and the defenses that stop it.What is a Progressive Web App (PWA)? How it works and when to use itA Progressive Web App (PWA) is a website built with web platform technologies that feels like a native installed app — it can be installed on a device, work offline, and run in the background. Here's how PWAs work, what they need, and when they make sense.What is Server-Side Rendering (SSR)? How it works and when to use itServer-side rendering generates the full HTML for a page on the server in response to a request — delivering a complete, crawlable page to the browser. Here's how SSR works, how it compares to client-side rendering, and when it makes sense for your project.What is SQL injection? How it works and how to prevent itSQL injection is one of the most common web vulnerabilities — this guide explains how it works, the main attack types, and the secure coding practices that prevent it.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 WebAssembly (WASM)? How it works and when to use itWebAssembly is a binary instruction format for a stack-based virtual machine — a portable compilation target that lets you run C, C++, Rust, and other compiled languages in the browser and beyond. Here's how it works and when it's worth using.What is XSS (Cross-Site Scripting)? How it works and how to prevent itCross-Site Scripting (XSS) lets an attacker run their own JavaScript in another user's browser. This guide explains how the three types work and the defenses that stop them.What are Core Web Vitals? LCP, INP, and CLS explainedCore Web Vitals are a set of Google metrics that measure the real-user experience of a web page: loading, interactivity, and visual stability. Learn what LCP, INP, and CLS measure, their target thresholds, and how to improve them.What is a Content Security Policy (CSP)? How CSP works and how to deploy itA Content Security Policy (CSP) is an HTTP security header that tells a browser which resources a page is allowed to load. Learn how CSP works, what directives are available, and how to deploy it without breaking your site.What is web accessibility (a11y)? WCAG principles and practical techniquesWeb accessibility (a11y) means designing sites that anyone can use, regardless of ability. This guide explains the four WCAG principles — perceivable, operable, understandable, robust — and practical techniques: semantic HTML, keyboard navigation, alt text, and color contrast.What is CORS? Cross-Origin Resource Sharing explainedCross-Origin Resource Sharing (CORS) is the mechanism browsers use to allow or block requests between different origins. This guide explains how CORS works, why it exists, common errors, and how to fix them.What is CSS Specificity? Selectors, Specificity, and the Cascade ExplainedCSS specificity is the algorithm browsers use to pick which CSS rule wins when two declarations target the same element and property. This guide explains selectors, specificity calculation, the cascade, and inheritance — with practical examples.What is the JavaScript event loop? How the call stack, task queue, and microtask queue workThe JavaScript event loop is the runtime model that lets single-threaded JavaScript run asynchronous code. Learn how the call stack, the task queue, and the microtask queue cooperate, and why Promise callbacks fire before setTimeout.Flexbox vs Grid: which CSS layout should you choose?Flexbox and CSS Grid are two layout systems built into the browser. Flexbox is one-dimensional (a row or a column); Grid is two-dimensional (rows and columns at once). Learn how each one works, when to reach for it, and how to combine them.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 HTML? How HyperText Markup Language works and why it mattersHTML is the foundation of every web page. Learn what HyperText Markup Language is, how HTML elements and tags work, why semantic HTML matters for SEO and accessibility, and how HTML fits with CSS and JavaScript.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 responsive web design? How it works (media queries, fluid grids, images)Responsive web design (RWD) makes pages render well on every screen size. Learn how media queries, fluid grids, fluid images, and the viewport meta tag work together.What is a Service Worker? How it works and when to use itA service worker is a JavaScript file the browser runs in the background, separate from the page. It sits between your app and the network and lets you cache assets, intercept requests, work offline, and receive push notifications. Here's how it works, what its lifecycle looks like, and when to reach for one.What is lazy loading? How deferring resources speeds up the webLazy loading is a performance strategy that defers non-critical resources (images, iframes, JavaScript, CSS) until they are needed. Learn what can be lazy-loaded, the native loading attribute, the Intersection Observer API, and when lazy loading helps or hurts. 