revision:
Provides an accessible, long-text description of any SVG container element or graphics element. Text in a <desc> element is not rendered as part of the graphic. If the element can be described by visible text, it is possible to reference that text with the "aria-describedby" attribute. If "aria-describedby" is used, it will take precedence over <desc>.
The hidden text of a <desc> element can also be concatenated with the visible text of other elements using multiple IDs in an "aria-describedby" value. In that case, the <desc> element must provide an ID for reference.
Attributes: includes global attributes.
example
codes:
<svg viewBox="0 0 10 7">
<circle cx="5" cy="3" r="3">
<desc>I'm a circle and that description is here
to demonstrate how I can be described, but is it really
necessary to describe a simple circle like me? </desc>
</circle>
</svg>
Adds metadata to SVG content. Metadata is structured information about data. The contents of <metadata> should be elements from other XML namespaces such as RDF, FOAF, etc.
Attributes: includes global attributes
Provides an accessible, short-text description of any SVG container element or graphics element. Text in a <title> element is not rendered as part of the graphic, but browsers usually display it as a tooltip. If an element can be described by visible text, it is recommended to reference that text with an "aria-labelledby" attribute rather than using the <title> element.
Attributes: includes only global attributes
example
codes:
<svg viewBox="0 0 20 10">
<circle cx="5" cy="5" r="4">
<title>I'm a circle</title>
</circle>
<rect x="11" y="1" width="8" height="8">
<title>I'm a square</title>
</rect>
</svg>