Since absolutely positioned elements do not behave like the level of a block of elements and do not flow one after another, as usual, a <div>.
You will need to set the width and height for the div, which is absolutely positioned, depending on what it contains.
Your absolutely positioned element will be located relative to the first parent element in which it is located. So a simple example:
'gotcha' position: relative;
<div style="width: 500px; height: 500px; position: relative; border: 1px solid blue;">
<div style="width: 150px; height: 150px; position: absolute; left: 10px; top: 10px; border: 1px solid red;">
I'm positioned absolutely to my parent.
</div>
</div>