> ## Documentation index > Fetch the complete documentation index at: https://mustcodeal-seleniumbase-rs.docs7.io/llms.txt > Ask it with GET https://mustcodeal-seleniumbase-rs.docs7.io/ask?q=. Short keywords rank best. > Use these to discover all available pages before exploring further. > Feature requests: https://mustcodeal-seleniumbase-rs.docs7.io/feature-requests.md lists what users asked for and how to vote for a request or add one. > Page rating: `GET https://mustcodeal-seleniumbase-rs.docs7.io/feedback?path=/concepts/overview&helpful=true` (or `false`) records whether this page helped. An optional `comment` (URL-encoded, at most 500 characters) says what was missing or wrong. It is anonymous and needs no key. Comments hold no code, secrets or personal data. # How it works > A map of the How it works section, in a learning order: how a page loads and how a browser is built, how WebDriver, CDP and MCP drive it, the DOM and JavaScript, the network, sessions, security, building and shipping web apps, and mobile, accessibility, SEO and media. **In short:** these pages explain the web from the bottom up, in plain words, for people who automate browsers and need to know why a test behaves the way it does. Each page ends with the part that matters to seleniumbase-rs, so the explanation and the API sit side by side. Read them in order, or jump to the group that matches the problem you have. ## Where to start | If a test... | Start with | |---|---| | passes sometimes and fails sometimes | [How a page loads and renders](/concepts/how-a-page-loads), then [JavaScript, events and the Web APIs](/concepts/javascript-and-events) | | cannot find an element, or finds the wrong one | [Selectors, the DOM and frameworks](/concepts/selectors-and-the-dom) | | is blocked, or meets a CAPTCHA | [Detection and spoofing](/concepts/detection), then [CAPTCHAs](/concepts/captchas) | | loses its login, or needs to skip the login | [Sessions, cookies, storage and logging in](/concepts/sessions-and-state) | | fails only on CI or in a container | [Containers, CI/CD and deployment](/concepts/containers-and-deployment), then [Browser architecture](/concepts/browser-architecture) | | fails on one site after the site was deployed | [Bundling, compression and caching](/concepts/bundling-and-caching) | | needs a proxy, a fake response or a recording of the traffic | [The network, TCP, proxies and traffic capture](/concepts/network) | | should be driven by an AI assistant | [AI, machine learning and the Model Context Protocol](/concepts/mcp) | ## Start here - [How a page loads and renders](/concepts/how-a-page-loads): from a URL to bytes to pixels, what "loaded" really means, and why automation needs waits. - [How a modern browser is built](/concepts/browser-architecture): rendering and JavaScript engines, processes, the sandbox, targets, headless mode, profiles and launch flags. ## Automating a browser - [WebDriver and drivers](/concepts/webdriver): the W3C protocol, the driver binary, sessions, element references and why tests flake without waits. - [The DevTools Protocol and developer tools](/concepts/cdp): the panels you use by hand and the WebSocket protocol behind them, which the pure CDP engine speaks directly. - [AI, machine learning and MCP](/concepts/mcp): how an assistant drives a browser through the Model Context Protocol, and how to test sites that contain ML. - [Detection and spoofing](/concepts/detection): the signals a site reads to tell a program from a person, and where the library answers each one. - [CAPTCHAs](/concepts/captchas): what they are for, how bot-management scoring works, and what the library does and does not do. - [Browser extensions](/concepts/browser-extensions): Manifest V3, content scripts, and how automation loads an extension. ## Pages and the DOM - [Selectors, the DOM and frameworks](/concepts/selectors-and-the-dom): the tree you point at, CSS and XPath, shadow DOM, iframes, what React, Vue and Angular leave behind, and stable selectors. - [JavaScript, events and the Web APIs](/concepts/javascript-and-events): the event loop, trusted input, auto-waiting, observers, and calling browser APIs from a test. ## Network and the wire - [The network, TCP, proxies and traffic capture](/concepts/network): sockets, HTTP, DNS, TLS, proxies, interception, HAR recording and what a connection reveals. - [Bundling, compression and caching](/concepts/bundling-and-caching): why the code a browser runs is not the code that was written, and why stale content breaks tests. ## State, identity and forms - [Sessions, cookies, storage and logging in](/concepts/sessions-and-state): cookies, web storage, profiles, OAuth, JWTs, TOTP, passkeys, and saving a signed-in state. - [Forms](/concepts/forms): input types, validation, encodings, uploads, CSRF tokens and framework-controlled inputs. ## Security - [Web security and browser policies](/concepts/web-security): the OWASP Top 10, the same-origin policy, CORS, CSP and the other rules a browser enforces, and what a test may check. - [Encryption and certificates](/concepts/encryption): encoding, hashing and encryption told apart, signatures, the chain of trust and keeping secrets out of test code. ## Building and shipping web apps - [Frontends, backends, APIs and the shapes inside a server](/concepts/frontends-backends-and-apis): what sits behind a page, from reverse proxies and REST to CRUD, middleware and serverless. - [Containers, CI/CD and deployment](/concepts/containers-and-deployment): Git, CI, Docker, Compose, deployment strategies and where browser tests run. - [Modern web technologies, eras and peer-to-peer](/concepts/modern-web): single-page apps, service workers, WebAssembly, WebRTC, HTTP/3, passkeys, Web3 wallets and P2P. - [Telemetry and observability](/concepts/telemetry-and-observability): logs, metrics, traces, analytics scripts and the library's own logging. ## Reach: mobile, accessibility, SEO and media - [The mobile web and accessibility](/concepts/mobile-and-accessibility): responsive design, device emulation, the accessibility tree and role selectors. - [Crawlers, spiders and SEO](/concepts/crawlers-and-seo): crawl frontiers, robots.txt, politeness, and what search engines need from a page. - [Audio and video](/concepts/media-and-video): codecs, adaptive streaming, autoplay, DRM and checking playback from tests. ## Reference - [Glossary](/glossary): short definitions of every term used in these pages.