background color for body element with predefined height in css

I have a html page which looks like this

body {
  height: 200px;
  background-color: lightblue;
  padding: 0px;
  border: 1px solid red;
}

<html>

<head>
</head>

<body>
  <p> First para </p>
  <p> Second para </p>

</body>

</html>

Here I specified body height as 200px and background-color for body element as "lightblue". Why is the background-color for body getting applied to the whole page and not only 200px height of the body?