What is HTML?

Definition
"Hypertext Markup Language (HTML) is the standard markup language for creating web pages and web applications. With Cascading Style Sheets (CSS) and JavaScript, it forms a triad of cornerstone technologies for the World Wide Web."


Web Pages
A web page is a document that can be viewed on a web browser. It can contain text, images, sounds, animations, videos and hyperlinks to other web pages. Most web pages are written using HTML, HTML5, XML and CSS.


Tags
HTML elements are delineated by tags, written using angle brackets. Tags such as <img /> and <input /> directly introduce content into the page. Other tags such as <p> surround and provide information about document text and may include other tags as sub-elements. Browsers do not display the HTML tags, but use them to interpret the content of the page.





Implementing on a Web Platform as a Number of Advantages and Disadvantages.

Advantages
Code solution runs inside a web platform so may not have full access to the underlying operating system or hardware, making it secure. Easy to integrate media such as images, video and music. Easy to link to other resources, e.g spreadsheets, documents, electronic slideshows. Code does not need to be installed. Code will always be the latest version as updated on the server. Usage of the code solution may be easier to monitor. Potentially good integration with other online services, eg, user support, email, instant messaging and social networking.


Disadvantages
The HTML, CSS and JavaScript is usually viewable in the web browser client, so is not secure and can be reverse-engineered and copied relatively easily. Requires a client web browser. Code running inside a web browser can be less efficient and slower than code running natively on an operating system. An internet connection is probably necessary. Security and access may become an issue. Requires hosting which is usually not free. A target for hackers and website defacement. Not all web browser clients support web technology standards equally well. Overall functionality can be limited when forced to work within a web browser environment.





What is CSS?

"Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language like HTML. CSS is a cornerstone technology of the World Wide Web, alongside HTML and JavaScript."

CSS is designed to enable the separation of presentation and content, including layout, colors, and fonts.This separation can improve content accessibility, provide more flexibility and control in the detail of the characteristics, allows multiple web pages to share the same formatting by specifying the relevant CSS in a separate .css file, and it also reduces the complexity and repetition in the structural content (html).