fit image in div without resizing code example

Example 1: css resize image to fit div no stretching

.div {
  background-image: url(../images/your-image.png);
  background-size:cover;
  background-position:center;
  background-repeat:no-repeat;
}

Example 2: make image stretch to fit div

Just apply without any changing any code
img {
width: 100%;
}