The HTML <figcaption> element represents a caption or a legend associated with a figure or an illustration described by the rest of the data of the <figure> element which is its immediate ancestor which means <figcaption> can be the first or last element inside a <figure> block. Also, the HTML Figcaption Element is optional; if not provided, then the parent figure element will have no caption.
The HTML <figure> element represents self-contained content, frequently with a caption (<figcaption>), and is typically referenced as a single unit. While it is related to the main flow, its position is independent of the main flow. Usually this is an image, an illustration, a diagram, a code snippet, or a schema that is referenced in the main text, but that can be moved to another page or to an appendix without affecting the main flow.
The HTML <head> element provides general information (metadata) about the document, including its title and links to its scripts and style sheets.
Heading elements implement six levels of document headings, <h1> is the most important and <h6> is the least. A heading element briefly describes the topic of the section it introduces. Heading information may be used by user agents, for example, to construct a table of contents for a document automatically.
The HTML <hr> element represents a thematic break between paragraph-level elements (for example, a change of scene in a story, or a shift of topic with a section). In previous versions of HTML, it represented a horizontal rule. It may still be displayed as a horizontal rule in visual browsers, but is now defined in semantic terms, rather than presentational terms.
The HTML <html> element (or HTML root element) represents the root of an HTML document. All other elements must be descendants of this element.
The HTML <ins> Element (or HTML Inserted Text) HTML represents a range of text that has been added to a document.
The HTML Label Element (<label>) represents a caption for an item in a user interface. It can be associated with a control either by placing the control element inside the <label> element, or by using the for attribute. Such a control is called the labeled control of the label element. One input can be associated with multiple labels.
The HTML <legend> Element (or HTML Legend Field Element) represents a caption for the content of its parent <fieldset>.
The HTML <li> element (or HTML List Item Element) is used to represent an item in a list. It must be contained in a parent element: an ordered list (<ol>), an unordered list (<ul>), or a menu (<menu>). In menus and unordered lists, list items are usually displayed using bullet points. In ordered lists, they are usually displayed with an ascending counter on the left, such as a number or letter.
The HTML <main> element represents the main content of  the <body> of a document or application. The main content area consists of content that is directly related to, or expands upon the central topic of a document or the central functionality of an application. This content should be unique to the document, excluding any content that is repeated across a set of documents such as sidebars, navigation links, copyright information, site logos, and search forms (unless the document's main function is as a search form).
The HTML <nav> element (HTML Navigation Element) represents a section of a page that links to other pages or to parts within the page: a section with navigation links.
The HTML <noscript> Element defines a section of html to be inserted if a script type on the page is unsupported or if scripting is currently turned off in the browser.
The HTML Embedded Object Element (<object>) represents an external resource, which can be treated as an image, a nested browsing context, or a resource to be handled by a plugin.
In a Web form, the HTML <optgroup> element  creates a grouping of options within a <select> element.
In a Web form, the HTML <option> element is used to create a control representing an item within a <select>, an <optgroup> or a <datalist> HTML5 element.
The HTML <p> element (or HTML Paragraph Element) represents a paragraph of text. Paragraphs are usually represented in visual media as blocks of text that are separated from adjacent blocks by vertical blank space and/or first-line indentation. The paragraph must be closed at end of the text "<p> text </p>" are requried to put the text between the paragraph. Paragraphs are block-level elements.
The HTML <param> Element (or HTML Parameter Element) defines parameters for <object>.
The HTML Script Element (<script>) is used to embed or reference an executable script within an HTML or XHTML document.
The HTML <section> element represents a generic section of a document, i.e., a thematic grouping of content, typically with a heading. Each <section> should be identified, typically by including a heading (<h1>-<h6> element) as a child of the <section> element.