HTML special characters are part of a character set, a coding, which goes beyond the available characters that can be recorded with a regular keyboard. They include Greek letters, mathematical symbols, arrows, currencies, dingbats (ornaments), and graphics, as well as checkmarks and symbols for copyrights and trademarks. HTML special characters are also referred to as masked characters and HTML entities.
If you'd like to review all special symbols please go here
<!--comment tag--> - the comment tag is used to insert comments in the source code. Comments are not displayed in the browsers. <div> tag is used as a container for HTML elements<span> element which is used to color a part of a text <h1-h6> tags are used to define HTML headings.<hr> tag is most often used to display a horizontal rule for a content separation in an HTML page. <br> tag inserts a single line break. <em> tag is used to define emphasized text. The content inside is typically displayed in italic. <strong> tag is used to define text with strong importance. The content inside is typically displayed in bold. <ul> tag defines an unordered (bulleted) list. <ol> tag defines an ordered list. An ordered list can be numerical or alphabetical. <li> tag is used to define each list item. <table> tag is used to create a table. <tr> tag defines a row in an HTML table. <th> tag defines a header cell in an HTML table. <td> tag defines a standard data cell in an HTML table. <dialog>tag defines a dialog box or subwindow. <inframe> tag specifies an inline frame. An inline frame is used to embed another document within the current HTML document.