NU Dasmariñas: Week 3 - Web Essentials & Technology PDF

Week 3– Web Essentials & Web Technology CTWBDEVL- Web System and Technologies OPENING PRAYER  Web System and Technology Road Map Week 3 Week 2: HTML (Lab) Week 3: Web Essential &...

Week 3– Web Essentials & Web Technology CTWBDEVL- Web System and Technologies OPENING PRAYER  Web System and Technology Road Map Week 3 Week 2: HTML (Lab) Week 3: Web Essential & Technology Course Orientation Week 2: Internet & WWW Week 3: CSS (Lab) Week 2 Week 1 Objectives: (Last Week) Discuss the history of INTERNET and how the WORLD WIDE WEB start. Understand the basic concepts and components of the internet and world wide web. Explain various terminology used in internet and Web At the end of the session, the students shall be able to: Understand the essential elements of the World Wide Web Identify the different basic internet protocol Identify the different HTTP status code Enumerate the various web technology use today. Web Essentials  The essential elements of the World Wide Web are the Web web browsers used to surf the Web, the server systems used to supply information to these browsers, and the Essentials computer networks supporting browser-server communication. The Internet The Internet The Internet traces its roots to a project of the U.S. Department of Defense’s then named Advanced Research Projects Agency, or ARPA. The ARPANET project was intended to support DoD research on computer networking. As this project began in the late 1960s, there had been only a few small experimental networks providing communication between geographically dispersed computers from different manufacturers running different operating systems. ARPANET project The purpose of ARPANET was to create a larger such network, both in order to electronically connect DoD-sponsored researchers and in order to experiment with and develop tools for heterogeneous computer networking E-mail was available on ARPANET beginning in 1972 The regional U.S. networks were often cooperative efforts between universities Several of the most widely used Internet protocols (FTP, SMTP) Local Area Network (LAN) NSF(National Science Foundation) Net NSFNET quickly supplanted ARPANET, which was officially decommissioned in 1990. At this point, NSFNET was at the center of the Internet, that is, the collection of computer networks connected via the public backbone and communicating across networks using TCP/IP. This same year, commercial Internet dial-up access was first offered. One of the arguments for allowing commercial traffic was economic: commercial traffic would increase network usage, leading to reduced unit costs through economies of scale. The Internet the Internet is the collection of computers that can communicate with one another using TCP/IP over an open, global communications network. Before describing how the World Wide Web is related to the Internet, we’ll take a closer look at several of the key Internet protocol. The Basic Internet Protocol Basic Internet Protocol A computer communication protocol is a detailed specification of how communication between two computers will be carried out in order to serve some purpose. For example, as we will learn, the Internet Protocol specifies both the high- level behavior of software implementing the protocol and the low-level details such as the specific fields of information that will be contained in a communication message, the order in which these fields will appear, the number of bits in each field, and how these bits should be interpreted. TCP/IP ▪Transmission Control Protocol (TCP) Establishes connections among sending and receiving computers Handles assembly of packets at point of transmission, and reassembly at receiving end ▪Internet Protocol (IP) - Specifies the addressing details for each packet Each packet is labelled with its origin and destination. ▪Four TCP/IP layers Network interface layer Internet layer Transport layer Application layer Internet (IP) Addresses ▪IPv4 o32-bit number oFour sets of numbers marked off by periods: 201.61.186.227 oClass C address: Network identified by first three sets, computer identified by last set ▪IPv6 o128-bit addresses, able to handle up to 1 quadrillion addresses (IPv4 can handle only 4 billion) HTTP (Hypertext Transfer Protocol) The hypertext transfer protocol (HTTP) was developed by Tim Berners-Lee in 1991 HTTP was designed to transfer pages between machines The client (or Web browser) makes a request for a given page and the Server is responsible for finding it and returning it to the client The browser connects and requests a page from the server HTTP (Hypertext Transfer Protocol) The server reads the page from the file system, sends it to the client and terminates the connection. Architecture of HTTP The Basic Characteristics of HTTP (Hyper Text Transfer Protocol): It is the protocol that allows web servers and browsers to exchange data over the web. It is a request response protocol. It uses the reliable TCP connections by default on TCP port 80. It is stateless means each request is considered as the new request. In other words, server doesn't recognize the user by default. Features of HTTP HTTP is connectionless: An HTTP request is initiated by the browser (HTTP client) as per the user's request for information. HTTP is simple: HTTP/2 does the encapsulation of HTTP messages into frames; i.e., HTTP is typically designed to be plain and human-readable. HTTP is extensible/customized: HTTP can be integrated with new functionality by providing a simple agreement between a client and a server. HTTP is stateless, but not session less: HTTP is stateless, which means there is no connection among two requests being consecutively carried out on the same connection Comprehensive addressing scheme URI (Uniform Resource Identifier) URI is a generic term for the names of all resources connected to the World Wide Web, and it is a sequence of characters that identifies a logical or physical resource URL (Uniform Resource Locator) URL is one subset of the URI. A URL is nothing more than the address of a given unique resource on the web that indicates the location of that unique web resource Comprehensive addressing scheme URN (Uniform Resource Name) A URN is an internet resource with a static name that remains valid even if its data is moved to another location.  HTTP Methods The GET method - is used to ask for a specific document - when you click on a hyperlink, GET is being used The HEAD method - is used to ask only for information about a document, not for the document itself. The POST method - used to transfer data from the client to the server; HTTP Status Code  HTTP Status Code 301 Moved Permanently Web Technology Web Technology Web Technology refers to the various tools and techniques that are utilized in the process of communication between different types of devices over the internet. A web browser is used to access web pages. Web Technology can be classified into the following sections: Web Browser World Wide Web Web Server Web Pages Web Development Web Development can be classified into two ways: Frontend Development: The part of a website that the user interacts directly is termed as front end. It is also referred to as the ‘client side’ of the application Backend Development: Backend is the server side of a website. It is the part of the website that users cannot see and interact. It is the portion of software that does not come in direct contact with the users. It is used to store and arrange data. Frontend Languages: The front-end portion is built by using some languages which are discussed below: Backend Languages: The back-end portion is built by using some languages which are discussed below: References: https://www.w3schools.com/whatis/ https://www.geeksforgeeks.org/web-technology/ https://developer.mozilla.org/en-US/docs/Web/HTTP