HTTP (Hypertext Transfer Protocol)
- Stateless Protocol : HTTP is stateless, meaning each request is independent and does not retain information about previous interactions.
- Request-Response Model : Communication occurs through a client-server model, where the client sends a request and the server responds.
- Text-Based : HTTP messages are human-readable and consist of methods like GET , POST , PUT , and DELETE.
- Port 80 : By default, HTTP operates on port 80.
Note
HTTP does not encrypt data, making it vulnerable to eavesdropping.
HTTPS (Hypertext Transfer Protocol Secure)
- Secure Version of HTTP : HTTPS adds a layer of encryption using protocols like SSL/TLS.
- Data Integrity and Confidentiality : Ensures that data is encrypted during transmission, protecting it from interception.
- Authentication : Uses digital certificates to verify the identity of the server.
- Port 443 : HTTPS operates on port 443.
Note
HTTPS is essential for secure transactions, such as online banking and shopping.
HTML (Hypertext Markup Language)
- Markup Language : HTML is used to structure web content using tags like <h1>, <p>, and <a>.
- Static Content : Defines the content and layout of web pages but does not handle dynamic behavior.
- Platform Independent: HTML files can be rendered by any web browser.
Example
HTML tags are enclosed in angle brackets, e.g., <h1>Title</h1>.
URL (Uniform Resource Locator)
- Web Address : A URL specifies the location of a resource on the internet.
- Components : Includes the protocol (e.g., https://), domain (e.g., www.example.com), and path (e.g., /index.html).
- Human-Readable: Designed to be easily understood and remembered by users.
Example
A URL like https://www.example.com/about points to the "about" page on the "example.com" domain using HTTPS.
XML (Extensible Markup Language)
- Self-Descriptive : XML uses tags to describe data, making it both human-readable and machine-readable.
- Hierarchical Structure : Data is organized in a tree-like structure with nested elements.
- Platform Independent : XML is widely used for data exchange between different systems.
Example
An XML document might look like this:
<student> <name>John Doe</name> <grade>A</grade> </student>
XSLT (Extensible Stylesheet Language Transformations)
- Transformation Language : XSLT is used to transform XML documents into other formats, such as HTML or plain text.
- Template-Based : Uses templates to define how elements should be processed and displayed.
- Declarative Syntax : Focuses on what should be done rather than how to do it.
Example
XSLT can convert an XML document into an HTML table for web display.
JavaScript
- Client-Side Scripting : JavaScript runs in the browser , enabling dynamic and interactive web pages.
- Event-Driven : Responds to events like clicks, form submissions, and mouse movements.
- Versatile : Can manipulate the DOM , validate forms, and communicate with servers using AJAX.
Example
A simple JavaScript function to display an alert:
function greet() { alert("Hello, World!"); }
CSS (Cascading Style Sheets)
- Styling Language : CSS is used to define the appearance of HTML elements, including colors, fonts, and layouts.
- Separation of Concerns : Keeps style separate from content, making web pages easier to maintain.
- Cascading Rules: Styles can be applied at different levels (inline, internal, external), with a hierarchy determining which rules take precedence.
Example
CSS can change the color of all <h1> elements to blue:
h1 { color: blue; }
Summary Table
| Technology | Characteristics |
|---|---|
| HTTP | Stateless, text-based, operates on port 80 |
| HTTPS | Encrypted, secure, operates on port 443 |
| HTML | Markup language, structures content, static |
| URL | Specifies resource location, human-readable |
| XML | Self-descriptive, hierarchical, data exchange |
| XSLT | Transforms XML, template-based, declarative |
| JavaScript | Client-side scripting, dynamic, event-driven |
| CSS | Styles HTML, separates content and design, cascading rules |
