The audio tag allows you to play audio from your browser. Audio sources are placed inside of the tag. There are also few notable attributes for the audio control, such as "autoplay" which starts the audio as soon as the page is opened (although this tag is blocked in chromium based browsers) and "controls" which shows the audio with a control UI from your browser.
Text that is placed inside of the audio tag only displays if the browser does not support audio.
<audio controls>
<source src="https://upload.wikimedia.org/wikipedia/commons/6/65/Star_Spangled_Banner_instrumental.ogg" type="audio/ogg">
Your browser does not support this tag :(
</audio>
Tag source from w3schools
The idiomatic text tag is used when some part of a text should be set apart from the rest. This tag is traditionally represented with italics, although it is not explicitly an italics tag.
There is also a very similar tag called <em> emphasis </em>, which actually does exactly the same thing. The only difference is in your heart.
Boy, I sure am having a wonderful day today.
I sure hope Bill will be here soon with the sandwiches that have the special seasoning on them.
Boy, I sure am having a <i>wonderful</i> day today.
I sure hope <i>Bill</i> will be here soon with the sandwiches that have the <em>special seasoning</em> on them.
Tag source from developer.mozilla.org
The button tag creates clickable buttons that are used with JavaScript or forms in your web page.
A button can can be represented by text or images and triggers an action when it is clicked.
The button type attribute is the general use case type, while other button types are used with forms. The event that occurs when a button is clicked is determined in its "onclick" attribute.
<button type="button" onclick="alert('CAWWWWWWW')">
<img src ="https://assets.stickpng.com/images/580b57fbd9996e24bc43bb51.png">
</button>
Tag source from geeks4geeks.org