CSS circle and oval can be created using border-radius on a div. For circle the horizontal and vertical radius of each corner is same, whereas for oval these should be different.
CSS circle
<style>
.circle {
background-color: lightgreen;
width: 100px; height: 100px;
border-radius: 50px;
}
</style>
<div class="circle"></div>CSS oval
<style>
.oval {
background-color: lightgreen;
width: 200px; height: 100px;
border-radius: 100px/50px;
}
</style>
<div class="oval"></div>
