HTML Entities are a piece of text that enables you to add a wide range of characters to an HTML document.
It always begins with an ampersand ( & ) and ends with a semicolon ( ; ).
Some characters are reserved in HTML and they have special meaning when used in HTML document. For example, when using lesser than (<) symbol, your webpage will render the following text as an HTML tag. So, it is necessary to display the lesser than (<) like symbols using HTML entity.