Why do we need a <fieldset>
tag? Whatever purpose it serves is probably a subset of the form tag.
I looked up some info on W3Schools, which says:
<fieldset>
tag is used to group related elements in a form.<fieldset>
tag draws a box around the related elements.More explanation for those who are mistaking "why it exists in specification" for "what it does". I think the drawing part is irrelevant, and I don't see why we need a special tag just to group some related elements in a form.
The most obvious, practical example is:
<fieldset>
<legend>Colour</legend>
<input type="radio" name="colour" value="red" id="colour_red">
<label for="colour_red">Red</label>
<input type="radio" name="colour" value="green" id="colour_green">
<label for="colour_green">Green</label>
<input type="radio" name="colour" value="blue" id="colour_blue">
<label for="colour_blue">Blue</label>
</fieldset>
This allows each radio button to be labeled while also providing a label for the group as a whole. This is especially important where assistive technology (such as a screen reader) is being used where the association of the controls and their legend cannot be implied by visual presentation.