K2 (55%) Web Components Flashcards
HTTP
HTTP = Hypertext Transfer Protocol
Set of rules used for accessing webpages over the browser
The protocol takes a request from the users browser to view webpage and makes a request to the web server to transmit this to the browser in the form of HTML file for the user to view
HTTPS
HTTPS = Secure Hypertext Transfer Protocol
This is the secure form of the HTTP protocol. It works in the same way but any data transmitted is encrypted so it cannot be hacked.
When sending personal data eg bank details over internet, always make sure the website is using HTTPS over HTTP
TSL / SSL
TSL = transport layer security
SSL = secure sockets layer
TSL AND its predecessor SSL are cryptographic protocols used to provide secure communication over the internet.
The protocol is designed to provide security and integrity of data when communicating between two devices.
Often done by ensuring connection is private or secure, by encrypting data being sent, the identity of at least one of the communicating parties is authenticated (using public key cryptography) and the connection is reliable, achieved by checking a packet of data for loss or alteration during transmission
Servers
A server is hardware running server software to provide user with contents of world wide web ( web server) or access to web applications ( applications server)
Web Server
Web servers primarily store webpages as HTML files and provide these on request to a user’s browser using the HTTP or https protocol
web service most commonly run a Linux operating system and most common platform is Apache
Application server
Application servers host and organisations application software so it is accessible to users online.
Common examples include office 365, Gmail or stay
Hosting
Hosting is provided by an ISP (Internet hosting company) who will store your files on their servers making them available over the Internet to you and your clients.
Examples of hosting include webpages, images and other related files, file storage such as dropbox or Google Drive, and video hosting services such as YouTube
Relational database management systems
Relational databases are collections of tables linked by shared relationships. Most databases used today follow this model.
Relational database management systems are software designed to store the data from relational databases.
The system allows the user to add, edit, remove or interact with the data held in the database easily. Common examples include Microsoft access, Oracle and MySQL
Content management systems
Content management system allow for the creation and management of digital content in a user friendly environment.
Systems often include the ability to create, edit or remove content, such as web pages (including text, images, video, audio) and automatically store data into the database this information is then stored on a server which allows it to be accessed over the Internet.
Common examples of content management system is included WordPress, Joomla and Drupal
Browsers
A web client (commonly referreed to as web browser) is an application designed to allow users to access web pages ove the internet.
Common examples include Internet explorer, edge, chrome, Firefox and Safari
Note the browser is not the same thing search engines. A setting is a web application accessed through a browser in the same way as other web pages
Web applications
Web applications are software designed to perform specific tasks
This could be a word processor, spreadsheet, browser, media player or game.
Applications can be downloaded and installed natively on the device as a desktop application or accessed over the Internet in the form of a web application
Search engines
Search engines (such as Google) are systems designed to locate resources over the Internet. this could be a web page, document, image or any other file stored on a web server.
Search engines rely on a database or index of webpages to locate information relevant to a users search
Markup language
Markup language is a way of marking up a document in a way that determines how it will be displayed when rendered as webpage
Most widely used markup language is HTML which uses tags to identify how text should be displayed
Markup language links
Example of a link in html…
<a>Google Homepage</a>
The tags are in angle brackets < > and site either side of the text to be displayed eg Google Homepage
These tags are read by browser and determine how link is formed
The ‘a’ tells the browser this tag is an attribute which will also include additional info
The ‘href=‘ tells the browser that thw attribute is a link and the contents of the “ “ following this contain the link address
When viewed in browser, only the Google Homepage is visible to the user but the text can be selected and in doing ao thw user will be take to link address
Web Crawlers
The index required by search engines is created and maintained by web crawlers.
This is software that ‘crawls’ pages in the index and follows any available links to find new content to add to the index.
This continues until there are no links left to follow and then the process repeats continuously so the index is constantly updated.
Search results
There are believed to be over 200 factors relating to how web results are positioned. While many of these factors are not explicitly available (to prevent people cheating the system), some of the major factors are…
Major factors for search result order
Meta data - meta tags and descriptions are lists of keywords on web pages relating to content. Specified by website owner and are not visible to anyone reading web page via browser but used by search engine to establish if page is relevant to a search.
Keywords - use of keywords in titles and heading can boost page’s ranking for that key term. Search engines also like web pages that use titles to structure the contents of a page, making it easier for user to read and find the relevant info.
Age of website in conjunction with update frequency - an older site regularly update will be viewed as more of an authority than a new site. But an older site that has not been updated in 10 years will not be considered as relevant as a newer site that is regularly updated
Relevancy of domain name to content and search term - if site with flowers.com domain name has pages about flowers it will be more relevant for a flowers related search. Even if they had a great page about chocolate this would not rate as highly on chocolate searches.
Keyword abuse
In 1980/90s people where overusing keywords to the point that it became difficult to read webpages.
The google algorithm is designed and regularly updated to penalise sites using such tactics.
SEO
SEO considers how search engines work and use this to ensure web content is designed to score highly in page rankings.
Good practices include:
- creatinf good quality content
- ensure website is mobile friendly
- Set a keywork or phrase relating to your content for each page
- provide meta description to briefly explain what article is about
- include images and ensure titles of image include keyword or phrase
- include links - links to own content where relevant and other high quality sources where relevant
- use short but relevant page titles incl keyword
- include a minimum of 300 words
- structure content with headings and subheadings ( incl keywords)
- does it read well? (Flesh reading ease test)
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Static webpages
A static page is delivered to user ‘as seen’
Everything a browser needs to display the page is contained in html file stored on web server.
Often written in html with css to provide additional styling or presentation instructions. Main content of page will be found in the html file which is interpreted by the browser
Dynamic webpages
Dynamic webpages will provide additional instructions to the browser to help them display pages in a way that is enhanced.
Dynamic pages begin as HTML files but will also include scripting languages such as javascript where content can change based on user input or interaction. Eg online forms with auto fill or suggested, slideshows where speed is determined by mouse position, auto play on video content
Cookies
Small pieces of data sent from website and stored on users computer by browser while browsing internet.
Allows user to be identified and tracked when using browser.
In 2002 the EU launched a policy required websites to obtain consent before using cookies to store data
Forms and registration
Cookies often used to remember pieces of info often entered into online forms eg name, address, passwords. As online forms are used for registration on various sites, this is the reason your browser can autocomplete entries when logging into sites as a registered user
Checkout
Cookies where originally designed to remember items in a shopping cart when browsing online store. This function is now more often handled by a database although cookies are used to identify which user is assigned to which basket
W3C / world wide web consortium
W3c is the main international standards organisation for the web. The purpose is to foster compatibility and agreement among industry members in the adoption of new standards.
Having standards and guidelines in place helps ensure the long term growth of the web eg the consortium tried to ensure all vendors use compatible versions of html ensuring consistency in how browsers display the same web page.
IRTF / Internet Engineering Task Force
IETF develops and promotes internet standards, in particular standards that comprise the internet protocol suite (TCP/IP) which determines the rules for communication across the internet
TCP and IP
Transmission Control Protocol
Internet Protocol
