.parent {
    background-color: sandybrown;
    padding: 10px;
    margin: 10px;
    height: 100px;
    border: 1px solid black;
}
.child {
    background-color: aqua;
    height: 20px;
    border: 1px solid black;
}

.general {
    position: relative;
}

.absolute {
    position: absolute;
    bottom: 30px;
    left: 30px;
}