Soon after its formation in mid '94, the W3C published the first draft of a concrete proposal, and early implementations were pioneered by the Arena and emacs-w3 browsers in the beginning of '95. The first 'mass-market' browser to adopt the stylesheet approach was MSIE, about a year later. While you can most certainly stretch the features of HTML to provide useful layout and presentation, the trend is going to be towards moving that aspect into style sheets. The first word between the angle brackets is the tag's name. A tag is therefore the basic 'item', and an attribute is some extra detail such as how to align the content.
Tags are case-insensitive .
You can write them in small letters, big letters, or any mixture. A common convention is to write them in caps so they stand out from the rest of the document. White space and line breaks will not affect the document appearance in a browser except when used inside certain special tags which we'll describe later. Some people find HTML can be hard to read. This need not be so if it's written tidily.