*Browsers and how they work.
Browsers are software applications that allow users to access and view information on the internet. They act as the intermediary between users and the web, enabling them to visit websites, interact with web content, and perform various online activities. Browsers retrieve and display web pages by following these general steps:
User Input: Users enter a URL (Uniform Resource Locator) or click on a link within the browser to request a specific web page.
URL Parsing: The browser parses the URL to extract the protocol (e.g., HTTP or HTTPS), domain name (e.g., example.com), and any additional path or query parameters.
DNS Lookup: The browser performs a Domain Name System (DNS) lookup to resolve the domain name into an IP address. It contacts DNS servers to obtain the correct IP address associated with the requested domain.
Establishing a Connection: Using the resolved IP address, the browser establishes a TCP (Transmission Control Protocol) connection with the web server hosting the requested website.
HTTP Request: The browser sends an HTTP (Hypertext Transfer Protocol) request to the web server. This request includes the requested resource (e.g., the specific web page) and additional headers that provide information to the server, such as the browser type and any cookies.
Server Processing: The web server receives the HTTP request, processes it, and generates an appropriate response. The server may perform tasks like accessing databases, executing server-side code, or retrieving requested files.
HTTP Response: The web server sends back an HTTP response containing the requested web page's content, along with an appropriate response status code (e.g., 200 for a successful response).
Rendering: The browser receives the HTTP response and begins rendering the web page. It interprets the HTML, CSS, JavaScript, and other resources included in the response.
HTML Parsing: The browser parses the HTML document, constructing the Document Object Model (DOM) tree that represents the structure of the web page. It creates a visual representation of the page, including text, images, links, and other elements.
CSS Styling: The browser applies CSS styles to the corresponding elements, determining how they should appear visually. It computes the final layout of the page based on the HTML structure and CSS rules.
JavaScript Execution: If the web page includes JavaScript code, the browser executes it, allowing for dynamic interactions, data manipulation, and other client-side functionality.
Rendering and Display: The browser combines the rendered content, applies any remaining visual effects, and displays the final web page in the user's browser window.
Throughout this process, the browser handles various tasks like managing cookies, caching resources, handling user input and interactions, and ensuring security measures are in place (e.g., blocking malicious websites or warning about insecure connections).
Popular browsers include Chrome, Firefox, Safari, Edge, and Opera. Each browser implements its rendering engine and may have additional features, developer tools, and performance optimizations, but they all follow similar fundamental principles in retrieving and displaying web content.
Revising the points once again:-
User Input
URL Parsing
DNS Lookup
Establishing a Connection
HTTP Request
Server Processing
HTTP Response
Rendering
HTML Parsing
CSS Styling
JavaScript Execution
Rendering and Display