Internet VS the World Wide Web
What is a persistent (permanent) cookie?
- a cookie that is stored on the users hard drive and only deleted when the expiry date is reached or the cookie is deleted by the user - They remain in operation on the user's computer even after the browser is closed or the website session is terminated - They remove the need to enter log in details every time a certain website is visited - Some websites use cookies to store more personal information or user preferences. however, this can only be done if the user has provided the website with certain personal information and agrees to it being stored. Legitimate websites will always encrypt any personal information stored in the cookie to prevent unauthorized use by a third party that has access to your cookie folder. - many countries have laws to protect users and these cookies are supposed to become deactivated after sic months (even if the expiry date has not yet been reached). Persistent cookies are a very efficient way of carrying data from one website session to another, or even between sessions on related websites; they remove the need to store massive amounts of data on the web server itself. Storing the data on the web server without using cookies would also make it very difficult to retrieve a user's data without requiring the user to log in every time they visit the website. Summary: » allow the website to remember users' passwords, email addresses and invoice details, so they won't have to insert all of this information every time they visit or every time they purchase something from that website » serve as a memory, enabling the website to recognise users every time they visit it » save users' items in a virtual shopping basket/cart » track internet habits and users' website histories or favourites/bookmarks » target users with advertising that matches their previous buying or surfing habits » store users' preferences (for example, recognise customised web pages) » are used in online financial transactions » allow progress in online games and quizzes to be stored » allow social networking sites to recognise certain preferences and browsing histories » allow different languages to be used on the web pages automatically as soon as users log on.
What is a session cookie?
- a cookie that is stored temporarily on a computer; it is deleted when the browser is closed or the website session ends - type of cookie is stored in temporary memory on the computer, doesn't actually collect any information from the user's computer and doesn't personally identify a user. Hence, session cookies cease to exist on a user's computer once the browser is closed or the website session is terminated. E.g.: when making online purchases. They keep a user's items in a virtual shopping basket.
What are cookies?
- small files or code stored on a user's computer They are sent by a web server to a browser on a user's computer. Each cookie is effectively a small look-up table containing pairs of (key, data) values, for example, (surname, Jones) (music, rock). Every time a user visits a website, it checks if it has set cookies on their browser before. If so, the browser reads the cookie which holds key information on the user's preferences such as language, currency and previous browsing activity. Cookies allow user tracking and maintain user preferences. Collected data can also be used to customise the web page for each individual user. For example, if a user buys a book online, the cookies remember the type of book chosen by the user and the web page will then show a message such as "Customers who bought Hodder IGCSE ICT also bought Hodder IGCSE Computer Science". There are two types of cookie: » session cookie » persistent (or permanent) cookie. If a cookie doesn't have an expiry date associated with it, it is always considered to be a session cookie.
What is a web server?
A computer connected to the Internet that stores the web pages for a website. They: - host a website - deal with client requests - have their own IP address
What is the hypertext transfer protocol (http) and hypertext transfer protocol secure (https)?
A set of rules that must be obeyed when transferring files across the internet. It is a way for clients and servers to send and receive requests and deliver HTML web pages - it is the fundamental protocol of the World Wide Web. When some form of security (for example, SSL or TLS) is used, then this changes to https (you will often see the green padlock in the status bar as well). The 's' stands for secure, and indicates a more secure way of sending and receiving data across a network (for example, the internet). - the same as http except it adds encryption and authentication for requesting and delivering HTML web pages - should be used whenever a website deals with sensitive information (passwords and bank account details)
What is the World Wide Web?
A set of software programs that enables users to access resources on the Internet via hypertext documents.
What is a web browser?
A software application for retrieving, presenting and traversing information resources on the World Wide Web. Software that allow users to access and display web pages on their device screens.
What is the World Wide Web?
A worldwide collection of electronic documents (websites and web pages) accessed via the internet. A set of software programs that enables users to access resources on the Internet via hypertext documents. - popular service on the internet - based on Hypertext transfer protocol - a way of accessing information
What is the internet?
A worldwide network of interconnected networks - rather a concept that something we can "touch" - relies on a physical infrastructure that allows networks and individual devices to connect to other networks and devices
What do web browsers do?
Browsers interpret/ render/ translate hypertext mark-up language (HTML) sent from websites and produce the results on the user's device(images, text, audio...).
What are the differences between the internet and World Wide Web?
Internet: • users can send and receive emails • allows online chatting (via text, audio and video] • makes use of transmission protocols (TCP] and internet protocols (IP) • it is a worldwide collection of interconnected networks and devices World Wide Web (WWW): • it is a collection of multimedia web pages and other information on websites • http(s) protocols are written using hypertext mark-up language (HTML) • uniform resource locators (URLs) are used to specify the location of web pages • web resources are accessed by web browsers • uses the internet to access information from web servers
Is Internet the same thing as the World Wide Web?
No, it is not
What is a uniform resource locator (URL)?
Text addresses used to access websites. A URL is typed into a browser address bar using the following format: protocol://website address/path/file name The protocol is usually either http or https. The website address is: » domain host (www), » domain name (website name), » domain type (.com, .org, .net, .gov, for example), » and sometimes country code (uk, .de, .cy, for example). The path is the web page, but is often omitted and it then becomes the root directory of the website (see example below). The file name is the item on the web page. For example: https://www.hoddereducation.co.uk/ict
What is a hypertext mark-up language (HTML)?
The language used to design, display and format web pages, and to write http(s) protocols.
What is a web page?
a hypertext document connected to the World Wide Web.
What is a Domain Name Server (DNS)? And how is a web page located?
a server that looks up domain names (URL) for websites (for example, www.hoddereducation. com) in order to find the IP addresses that a computer needs to locate the web servers (for example, 107.162.140.19] - URLs and domain name servers eliminate the need for a user to memorise IP addresses - The DNS process involves more than one server - DNS servers contain a database of URLs with the matching IP addresses 1) The user opens their browser and types in the URL (www.hoddereducation.co.uk) and the browser asks the DNS server (1) for the IP address of the website. 2) In this case, let's assume the DNS server can't find www.hoddereducation.co.uk in its database or its cache, so it sends out a request to a DNS server (2). 3) The DNS server (2) finds the URL and can map it to 107.162.140.19; this IP address is sent back to the DNS server (1) which now puts this IP address and associated URL into its cache/database. 4) This IP address is then sent back to the user's computer. 5) The computer now sets up a communication with the website server and the required pages are downloaded. HTML files are sent from the website server to the computer. The browser interprets the HTML which is used to structure content, and then displays the information on the user's computer. (Note: in this case, the IP address was found on the second DNS server.)
What are the feature of browsers?
» they have a home page » they can store a user's favourite websites /web pages (referred to as bookmarks) » they keep a history of websites visited by the user (user history) » they have the ability to allow the user to navigate forwards and backwards through websites/web pages already opened » many web pages can be open at the same time by using multiple tabs » they make use of cookies » they make use of hyperlinks that allow navigation between websites and we pages; links can be opened in one of two ways: either open in a new tab by using <ctrl> + <clicks> or open in the same tab by simply clicking on the link » data is stored as a cache » make use of JavaScript » they use an address bar
