Labeling

<label for="html-label">HTML Label</label>
<input id="html-label">

<input placeholder="Placeholder">

<input aria-label="Aria Label">

<label id="labelledby">aria-labelledby</label>
<input aria-labelledby="labelledby">

<label id="describedby">aria-describedby</label>
<input aria-describedby="describedby">
<input aria-describedby="describedby"
       aria-label="Aria Label">

<button><span class="sr-only">Close</span> X</button>
<button aria-label="Close">X</button>