how to fit the img in the given container in css code example

Example 1: fit an image inside a div

div{
   width:100%;
    height:250px;
    display:flex;
    justify-content:center;
    align-items:center;
    overflow:hidden
}
div img{
  flex-shrink:0;
    -webkit-flex-shrink: 0;
    max-width:70%;
    max-height:90%;
}

Example 2: make image stretch to fit div

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