Question

What is the purpose of the

<span></span>

element? And where should we use it?

Answer 1

From here:

Definition and Usage

The tag provides no visual
change by itself.

The tag provides a way to add a
hook to a part of a text or a part of
a document.

When the text is hooked in a span
element you can add styles to the
content, or manipulate the content
with for example JavaScript.

So, the short version is, it’s to style some text (without a paragraph or linebreak which is different from <div> tag)