when i use position:absolute in child block it does not refer parent block? [duplicate]

Question

In HTML,When you use the position:absolute css property in child block the absolute value is not taken from parent tag it refer from whole browser window. the sample code is shown below..

CSS

.parent {
    width: 400px;
    height: 400px;
    border: 1px solid green;
}

.child {
    position: absolute;
    width: 200px;
    height: 200px;
    border: 1px solid red;
    bottom: 0px;
}

Answer 1

If you want the arrange the child with in the parent block just add position:relative in the parent CSS