Learn how to create a fading overlay effect to an image, on hover:

Please use code given below:

CSS

.container {
  position: relative;
  width: 50%;
}

.image {
  display: block;
  width: 100%;
  height: auto;
}

.overlay {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  height: 100%;
  width: 100%;
  opacity: 0;
  transition: .5s ease;
  background-color: #008CBA;
}

.container:hover .overlay {
  opacity: 1;
}

.text {
  color: white;
  font-size: 20px;
  position: absolute;
  top: 50%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
  text-align: center;
}

HTML

<div class="container">
  <img src="https://www.developersmap.com/wp-content/uploads/2019/05/12-1.png" alt="Avatar" class="image">
  <div class="overlay">
    <div class="text">Hello World</div>
  </div>
</div>

OUTPUT

Hello World