Web Server
A web server is a software application that processes and responds to client requests over the internet using the HTTP (Hypertext Transfer Protocol) or HTTPS (HTTP Secure) protocol. The primary function of a web server is to deliver web pages and other content to clients, such as web browsers, on behalf of a website.
Here are some of the main functions of a web server:
- Serving web pages: When a client requests a web page, the web server retrieves the page from its storage location and sends it to the client’s web browser.
- Handling dynamic content: Web servers can process and execute scripts or applications that generate dynamic content on the fly, such as PHP, Python, or Ruby scripts.
- Managing user sessions: Web servers can store and manage session information to maintain the state of a user’s interaction with a website, such as login credentials, shopping cart contents, and preferences.
- Managing server-side resources: Web servers can manage and allocate resources, such as CPU, memory, and disk space, to ensure efficient and reliable operation.
- Load balancing: Web servers can distribute incoming client requests across multiple servers to balance the workload and prevent overload.
- Security: Web servers can implement various security measures, such as SSL/TLS encryption, firewalls, and access control, to protect against cyber threats and unauthorized access.
Overall, the functions of a web server are crucial for delivering web content and services to clients and ensuring the reliable and secure operation of websites and web applications.
Web Client
A web client, also known as a web browser, is an application that allows users to access and interact with content on the World Wide Web. Some of the key functions of a web client include:
- Rendering web pages: A web browser retrieves HTML, CSS, and JavaScript files from web servers and renders them into a viewable format for the user.
- Navigating between pages: Web browsers allow users to navigate between different web pages by following links, typing in URLs, or using bookmarks.
- Running web applications: Many web-based applications, such as Google Docs and Gmail, are run entirely within a web browser.
- Displaying multimedia content: Web browsers can display a wide range of multimedia content, including images, videos, and audio files.
- Managing user preferences: Web browsers allow users to customize their browsing experience by changing settings such as font size, default search engine, and home page.
- Ensuring security: Web browsers employ a variety of security measures to protect users from malware, phishing, and other online threats.
- Interacting with web services: Many web services, such as social media platforms and online marketplaces, rely on web clients to facilitate interactions between users and their content.
URL
A URL (Uniform Resource Locator) and a URN (Uniform Resource Name) are both types of Uniform Resource Identifier (URI) that are used to identify resources on the internet, but they differ in their purpose and format.
A URL is a type of URI that provides a specific location for a resource on the internet. It includes a protocol (such as HTTP or FTP), a domain name or IP address, and a path to the resource. URLs are used to locate and access resources such as web pages, images, and files.
For example, “https://www.example.com/index.html” is a URL that identifies the location of an HTML file on the web server “www.example.com” using the HTTPS protocol.
URN
A URN, on the other hand, is a type of URI that provides a persistent identifier for a resource that is independent of its location. It does not include information about the location of the resource but rather identifies the resource itself. URNs can be used to identify resources such as books, articles, or images.
For example, “urn:isbn:978-0-1234-5678-9” is a URN that identifies a specific book by its International Standard Book Number (ISBN), regardless of where it is located on the internet.
In summary, URLs are used to locate and access resources on the internet, while URNs are used to provide a persistent identifier for a resource that is independent of its location.
