Web(WWW)

1. MAC (Media Access Control) Address: • Definition: A MAC address is a unique identifier assigned to a network interface card (NIC) for communications on the physical network segment. • Structure: It consists of 48 bits, typically represented as six groups of two hexadecimal digits (e.g., 00:1A:2B:3C:4D:5E). • Usage: MAC addresses are used in the data link layer (Layer 2) of the OSI model. They facilitate communication within the same local network or LAN segment. • Example: A MAC address might look like 00:14:22:01:23:45. • Characteristics: • MAC addresses are unique to each network interface card (NIC). • They are assigned by the manufacturer and embedded in the hardware. • Used primarily in the data link layer (Layer 2) of the OSI mode -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- • 2. IP (Internet Protocol) Address: • Definition: An IP address is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. • Structure: There are two types of IP addresses: • IPv4: Consists of 32 bits, represented as four decimal numbers separated by periods (e.g., 192.168.0.1). • IPv6: Consists of 128 bits, represented as eight groups of four hexadecimal digits separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). • Usage: IP addresses are used in the network layer (Layer 3) of the OSI model. They are used for routing packets across different networks. • Example: An IPv4 address might look like 192.168.1.1, and an IPv6 address might look like 2001:0db8:85a3:0000:0000:8a2e:0370:7334. -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 3. Port Address: • Definition: A port address, or port number, is a 16-bit number used to identify specific processes or services within a device. • Structure: Port numbers range from 0 to 65535, with ports 0-1023 designated as well-known ports for common services (e.g., HTTP, FTP). • Usage: Ports are used in the transport layer (Layer 4) of the OSI model. They allow multiple network services to operate on the same IP address by directing traffic to the correct application. • Example: HTTP typically uses port 80, HTTPS uses port 443, and FTP uses port 21. • Characteristics: • Ports are used in the transport layer (Layer 4) of the OSI model. • They are essential for multiplexing services on a single device. • Well-known ports (0-1023) are reserved for common services, while registered ports (1024-49151) and dynamic/private ports (49152-65535) are used for less common applications. • --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 4. Specific-URL (Uniform Resource Locator): • Definition: A URL is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. • Structure: A URL typically includes the protocol (e.g., http, https), the domain name or IP address of the server, and a path to the resource. It can also include a port number, query parameters, and fragments. • Usage: URLs are used in the application layer (Layer 7) of the OSI model. They are essential for accessing web resources over the Internet. • Example: A URL might look like https://www.example.com/path/to/resource?query=example#fragment. URLs are human-readable and designed to be easy to remember and use. • URLs are human-readable and designed to be easy to remember and use. • -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- HTTP HTTPS The full form of HTTP is the Hypertext Transfer Protocol. The full form of HTTPS is Hypertext Transfer Protocol Secure. It is written in the address bar as http://. It is written in the address bar as https://. The HTTP transmits the data over port number 80. The HTTPS transmits the data over port number 443. It is unsecured as the plain text is sent, which can be accessible by the hackers. It is secure as it sends the encrypted data which hackers cannot understand. It is mainly used for those websites that provide information like blog writing. It is a secure protocol, so it is used for those websites that require to transmit the bank account details or credit card numbers. It is an application layer protocol. It is a transport layer protocol. It does not use SSL. It uses SSL that provides the encryption of the data. Google does not give the preference to the HTTP websites. Google gives preferences to the HTTPS as HTTPS websites are secure websites. The page loading speed is fast. The page loading speed is slow as compared to HTTP because of the additional feature that it supports, i.e., security. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Web (WWW) The term "Web," short for "World Wide Web," refers to an information system where documents and other web resources are identified by URLs (Uniform Resource Locators), interlinked by hypertext, and can be accessed over the Internet. The Web is a fundamental service that operates over the Internet and has profoundly transformed how people access and share information. Here’s a detailed overview of what the Web encompasses: 1. Basics of the Web: • Foundation: The Web is built on technologies such as HTTP (Hypertext Transfer Protocol) for communication between clients (browsers) and servers, HTML (Hypertext Markup Language) for structuring web pages, and URLs for addressing. • Web Pages: The fundamental components of the Web are web pages, which can include text, images, videos, and interactive elements. These pages are written in HTML and can be styled with CSS (Cascading Style Sheets) and made interactive with JavaScript. 2. Key Components: • Web Browsers: Software applications like Google Chrome, Mozilla Firefox, and Microsoft Edge that allow users to access and interact with web pages. • Web Servers: Computers that store, process, and deliver web pages to users. Popular web server software includes Apache, Nginx, and Microsoft's IIS. • Hyperlinks: Links that connect one web page to another, enabling easy navigation across different resources and sites on the Web. 3. Functionality: • Accessing Content: Users access the Web through browsers by entering URLs or using search engines. The browser sends an HTTP request to the server, which responds with the requested web page. • Interactivity: Modern web pages often include interactive elements created using JavaScript and can dynamically update content without needing to reload the entire page (e.g., through AJAX). 4. Evolution: • Web 1.0: The early Web, characterized by static web pages and limited interactivity. Content was primarily read-only. • Web 2.0: Marked by the advent of interactive web applications, user-generated content, and social media platforms. It emphasized user participation, collaboration, and sharing. • Web 3.0 (Semantic Web): The next evolution aims to make web content more machine-readable through the use of metadata and AI, enabling better data connectivity and smarter applications. 5. Impact and Applications: • Information Sharing: The Web has democratized access to information, making a vast amount of knowledge available to anyone with an internet connection. • E-Commerce: Enabled online shopping, digital transactions, and global trade. • Social Interaction: Facilitated social networking, communication, and collaboration through platforms like Facebook, Twitter, and LinkedIn. • Education: Provided platforms for online learning, educational resources, and virtual classrooms. --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Parameter Microprocessor Microcontroller Definition Microprocessors can be understood as the heart of a computer system. Microcontrollers can be understood as the heart of an embedded system. What is it? A microprocessor is a processor where the memory and I/O component are connected externally. A microcontroller is a controlling device wherein the memory and I/O output component are present internally. Circuit complexity The circuit is complex due to external connection. Microcontrollers are present on chip memory. The circuit is less complex. Memory and I/O components The memory and I/O components are to be connected externally. The memory and I/O components are available. Compact system compatibility Microprocessors can’t be used in compact system. Microcontrollers can be used with a compact system. Efficiency Microprocessors are not efficient. Microcontrollers are efficient. Zero status flag Microprocessors have a zero status flag. Microcontroller doesn’t have a zero status flag. Number of registers Microprocessors have less number of registers. Microcontrollers have more number of registers. Applications Microprocessors are generally used in personal computers. Microcontrollers are generally used in washing machines, and air conditioners Cost High Less Power Consumption High Low Replace Difficult Easy Features of Microprocessor Here are some important features of Microprocessor: • Offers built-in monitor/debugger program with interrupt capability • Large amount of instructions each carrying out a different variation of the same operation • Offers Parallel I/O • Instruction cycle timer • External memory interface Features of Microcontroller Here are some important features of Microcontroller: • Processor reset • Program and Variable Memory (RAM) I/O pins • Device clocking central processor • Instruction cycle timers Applications of Microprocessor Microprocessors are mainly used in devices like: • Calculators • Accounting system • Games machine • Complex industrial controllers • Traffic light • Control data • Military applications • Defense systems • Computation systems Applications of Microcontroller Microcontrollers are mainly used in devices like: • Mobile phones • Automobiles • CD/DVD players • Washing machines • Cameras • Security alarms • Keyboard controllers • Microwave oven • Watches • Mp3 players