Why are relative divs not generating height? - html

Question

I have a 2 column grids. In column 1, there will be multiple instances of one div. Inside the one div there are two divs positioned absolutely - a number and a description. For some reason when I have multiple divs, they stack ontop of one another, which is because the 'template' div has no height.
Why a height is not automatically generated by the content within that div?
.main {
position: relative;
margin: 25px 0;
display: block;
}
.col1 {
width: 200px;
position: absolute;
left: 0;
}
.col2 {
width: 200px;
position: absolute;
right: 0;
}
.indicator {
width: 10px;
height: 10px;
background-color: #0f0;
color: #454;
position: absolute;
left: 0;
}
.text {
position: absolute;
right: 0;
}
.box {
position: relative;
}
<div class="main">
<div class="col1">
<div class="box">
<div class="indicator">
1
</div>
<div class="text">
Text text text text text text text text text text text text text text text text text text text text text text text text text.
</div>
</div>
<div class="box">
<div class="indicator">
1
</div>
<div class="text">
Text text text text text text text text text text text text text text text text text text text text text text text text text.
</div>
</div>
<div class="box">
<div class="indicator">
1
</div>
<div class="text">
Text text text text text text text text text text text text text text text text text text text text text text text text text.
</div>
</div>
<div class="box">
<div class="indicator">
1
</div>
<div class="text">
Text text text text text text text text text text text text text text text text text text text text text text text text text.
</div>
</div>
</div>
<div class="col2">
Col 2 content.
</div>
</div>
​Fiddle:
http://jsfiddle.net/techydude/UcFXX/1/
This is a very basic question, but I would rather understand the reasoning behind the issue without creating a work around by adding height.

Answer 1

Absolute positioning removes the element from the "flow", so as far as its parent is concerned, it's not really there and it isn't calculated as part of the parent's height.