a) STRUCTURAL TAGS

Tag	Description
`<a>`	Defines a hyperlink.
`<article>`	Defines an article.
`<aside>`	Defines some content loosely related to the page content.
`<body>`	Defines the document's body.
`<br>`	Produces a single line break.
`<details>`	Represents a widget from which the user can obtain additional information or controls on-demand.
`<div>`	Specifies a division or a section in a document.
`<h1> to <h6>`	Defines HTML headings.
`<head>`	Defines the head portion of the document that contains information about the document.
`<header>`	Represents the header of a document or a section.
`<hgroup>`	Defines a group of headings.
`<hr>`	Produce a horizontal line.
`<html>`	Defines the root of an HTML document.
`<footer>`	Represents the footer of a document or a section.
`<nav>`	Defines a section of navigation links.
<p>	Defines a paragraph.
<section>	Defines a section of a document, such as header, footer etc.
<span>	Defines an inline styleless section in a document.
<summary>	Defines a summary for the <details> element.

b) METADATA TAGS

Tag	Description
<base>	Defines the base URL for all linked objects on a page.
<link>	Defines the relationship between the current document and an external resource.
<meta>	Provides structured metadata about the document content.
<style>	Inserts style information (commonly CSS) into the head of a document.
<title>	Defines a title for the document.

Tag	Description
<button>	Creates a clickable button.
<datalist>	Represents a set of pre-defined options for an <input> element.
<fieldset>	Specifies a set of related form fields.
<form>	Defines an HTML form for user input.
<input>	Defines an input control.
<keygen>	Represents a control for generating a public-private key pair.
<label>	Defines a label for an `<input>` control.
<legend>	Defines a caption for a `<fieldset>` element.
<meter>	Represents a scalar measurement within a known range.
<optgroup>	Defines a group of related options in a selection list.
<option>	Defines an option in a selection list.
<select>	Defines a selection list within a form.
<textarea>	Defines a multi-line text input control (text area).

Tag	Description
<abbr>	Defines an abbreviated form of a longer word or phrase.
<acronym>	Defines an acronym.
<address>	Specifies the author's contact information.
<b>	Displays text in a bold style.
<bdi>	Represents text that is isolated from its surrounding for the purposes of bidirectional text formatting.
<bdo>	Overrides the current text direction.
<big>	displays text in a large size.
<blockquote>	Defines a long quotation.
<cite>	Indicates a citation or reference to another source.
<code>	Specifies text as computer code.
<del>	Specifies a block of deleted text.
<dfn>	Specifies a definition.
<em>	Specifies emphasized text.
<i>	Displays text in an italic style.
<ins>	Defines a block of text that has been inserted into a document.
<kbd>	Specifies text as keyboard input.
<mark>	Represents text highlighted for reference purposes.
<output>	Represents the result of a calculation.
<pre>	Defines a block of preformatted text.
<progress>	Represents the completion progress of a task.
<q>	Defines a short inline quotation.
<rp>	Provides fall-back parenthesis for browsers that that don't support ruby annotations.
<rt>	Defines the pronunciation of character presented in a ruby annotations.
<ruby>	Represents a ruby annotation.
<samp>	Specifies text as sample output from a computer program.
<small>	Displays text in a smaller size.
<strong>	Indicate strongly emphasized text.
<sub>	Defines subscripted text.
<sup>	Defines superscripted text.
<tt>	Displays text in a teletype style.
<var>	Defines a variable.
<wbr>	Represents a line break opportunity.

Tag	Description
<dd>	Specifies a definition for a term in a definition list.
<dl>	Defines a definition list.
<dt>	Defines a term (an item) in a definition list.
<li>	Defines a list item.
<ol>	Defines an ordered list.
<menu>	Represents a list of commands.
<ul>	Defines an unordered list.

Tag	Description
<caption>	Defines the title of a table.
<col>	Defines attribute values for one or more columns in a table.
<colgroup>	Specifies attributes for multiple columns in a table.
<table>	Defines a data table.
<tbody>	Groups a set of rows defining the main body of the table data.
<td>	Defines a cell in a table.
<tfoot>	Groups a set of rows summarizing the columns of the table.
<thead>	Groups a set of rows that describes the column labels of a table.
<th>	Defines a header cell in a table.
<tr>	Defines a row of cells in a table.

Tag	Description
<noscript>	Defines alternative content to display when the browser doesn't support scripting.
<script>	Places script in the document for client-side processing.

Tag	Description
<audio>	Embeds a sound, or an audio stream in an HTML document.
<canvas>	Defines a region in the document, which can be used to draw graphics on the fly via scripting (usually JavaScript).
<embed>	Embeds external application, typically multimedia content like audio or video into an HTML document.
<figcaption>	Defines a caption or legend for a figure.
<figure>	Represents a figure illustrated as part of the document.
<frame>	Defines a single frame within a frameset.
<frameset>	Defines a collection of frames or other frameset.
<iframe>	Displays a URL in an inline frame.
`<noframes>`	Defines an alternate content that displays in browsers that do not support frames.
<source>	Defines alternative media resources for the media elements like <audio>or <video>.
<time>	Represents a time and/or date.
<video>	Embeds video content in an HTML document.

Tag	Description
<area>	Defines a specific area within an image map.
`<object>`	Defines an embedded object.
<param>	Defines a parameter for an object or applet element.
<img>	Displays an inline image.
`<map>`	Defines a client-side image-map.