Answer 1

A quick explanation of tags, elements, and attributs in HTML:

An element in HTML represents some kind of structure or semantics and generally consists of a start tag, content, and an end tag. The following is a paragraph element:
<p>
This is the content of the paragraph element.
</p>

Tags are used to mark up the start and end of an HTML element.
A start tag consists of an opening angle bracket (<) followed by the element name, and a closing angle bracket (>).
A start tag with no attributes:
<p>
A start tag with an attribute:
<p class="info">
End tags consist of an opening angle bracket followed by a forward slash, the element name, and a closing angle bracket:
</p>

An attribute defines a property for an element, consists of an attribute/value pair, and appears within the element's start tag. An element's start tag may contain any number of space separated attribute/value pairs.

<img src="foobar.gif" alt="A foo can be balanced on a bar.">

Answer 2

Tags, attributes, content between tags in single word are called element.