Elements can have attributes. This test page has sample paragraphs with attributes to explore.
The next paragraph has attributes. Some are custom attributes, and one "original-title" was added using JavaScript.
This paragraph has attributes
The next paragraph has an id, and a custom attribute called "nextid" which is used when adding additional attributes via JavaScript when the button is clicked e.g. "custom-{nextid}.
This paragraph has dynamic attributes
The next paragraph has a static id, and attributes that are dynamically updating regularly.
This paragraph has dynamic attributes