The HTML id attribute is used to specify a unique id for an HTML element.
You cannot have more than one element with the same id in an HTML document.
The id Attribute
The id attribute specifies a unique id for an HTML element. The value of the id attribute must be unique within the HTML document.
The id attribute is used to point to a specific style declaration in a style sheet. It is also used by JavaScript to access and manipulate the element with the specific id.
The syntax for id is: write a hash character (#), followed by an id name. Then, define the CSS properties within curly braces {}.
In the following example we have an <h1> element that points to the id name “myHeader”. This <h1> element will be styled according to the #myHeader style definition in the head section: Continue reading HTML id Attribute