Before we can create our first web page, we need to create a file that our service will recognize as a web page. To do this, we can open our chosen text editor (see a short list of potentials in the section on Integrated Development Environments), and create a new document if one was not created automatically. We will immediately select “Save As” from your editor’s File menu, and give your new page its name. If this is going to be the front page, or first page you want a user to see for your site, you should name it index. Index is the default file name most web servers look for in any folder of your website; it saves your users from having to know and type the page name as part of the URL.
In many text editors, underneath or near where you enter the file name is another drop down selector that allows you to pick a file type. This is the extension (what comes after the period in the file name), or file type, that identifies what kind of data the file represents. This tells our operating system, applications, and browsers what conventions were used to create the content so it can be reassembled into usable form. Since we are creating a basic web page, we will use the .htm extension (.html is also acceptable, just be consistent to make your life easier). If your editor does not have .htm or .html in its list, then select “All” and make index.htm your file name.
If you ever come across an unfamiliar extension and want to know more about it, sites like filext.com can help you determine what programs can open it and what it is for.
Once we have saved our file as index.htm, we are ready to begin. Saving as soon as we create a file is useful as the text editor will then know what syntax is expected. This will enable features like color coding and highlighting that your editor supports.
Every HTML page we create should declare its document type (doctype) in the first line. This will identify which spec of HTML is included so the browser knows how to interpret the tags within. Earlier version of the HTML specifications used two definitions for HTML: HTML 4.01 and XHTML. Both of these contained two additional properties of strict and transitional.
With HTML5, much of this has been eliminated, leaving one general doctype declaration of <!DOCTYPE html>. This should be the first line of code in any HTML page you create. We will not cover the older doctype formats as all of our examples will focus on HTML5. Keep in mind, though, that code examples you find online with anything other than the tag above may be outdated approaches to what is shown.
Keywords, search terms: xml, html, css, dom, document markup,
W3C Documentation for XML: http://www.w3.org/TR/2004/REC-xml11-20040204/
W3C Documentation for CSS: http://www.w3.org/Style/CSS/
W3C Specifications for HTML:http://www.w3.org/community/webed/wiki/HTML/Specifications