html - Display one content after another using CSS keyframes

Question

I have the following HMTL and CSS:

.parent{
 height: 10%;
 width: 100%;
 float: left;	 
}
 
.content1{
 height: 100%;
 width: 20%;
 background-color: blue;
 float: left;
}
 
 .content2{
 height: 100%;
 width: 20%;
 background-color: red;
 float: left;
}
 
 .content3{ 
 height: 100%;
 width: 20%;
 background-color:yellow;
 float: left;
}
 
.content4{
 height: 100%;
 width: 20%;	
 background-color: green;
 float: left;
}
 
 .content5{
 height: 100%;
 width: 20%;
 background-color: orange;
 float: left;
}
 
 
 
.parent {
 animation-name: animation_01;
 animation-duration:5s;
 animation-iteration-count:1;
 animation-fill-mode: forwards;
 }


@keyframes animation_01 {
	
    0% {
    opacity: 0
    }
 
    20% {
    opacity: 1
    }
 
    40% {
    opacity: 0
    }
 
    60% {
    opacity: 1
    }
 
    80% {
    opacity: 0
    }
 
    100% {
    opacity: 1
    }
 
  }

}

<div class="parent">
	<div class="content1">Here goes content1</div>
	<div class="content2">Here goes content2</div>
	<div class="content3">Here goes content3</div>
	<div class="content4">Here goes content4</div>
	<div class="content5">Here goes content5</div>
 </div>

Answer 1

You need to animate each div. You can use the same animation for all. For each div set animation-delay. Here is an example with the animation you defined in the question:

.parent {
  height: 10%;
  width: 100%;
  float: left;
}

.parent div {
  animation-name: animation_01;
  animation-duration: 5s;
  animation-iteration-count: 1;
  animation-fill-mode: forwards;
  opacity: 0;
}

.content1 {
  height: 100%;
  width: 20%;
  background-color: blue;
  float: left;
}

.content2 {
  height: 100%;
  width: 20%;
  background-color: red;
  float: left;
  animation-delay: 1s;
}

.content3 {
  height: 100%;
  width: 20%;
  background-color: yellow;
  float: left;
  animation-delay: 2s;
}

.content4 {
  height: 100%;
  width: 20%;
  background-color: green;
  float: left;
  animation-delay: 3s;
}

.content5 {
  height: 100%;
  width: 20%;
  background-color: orange;
  float: left;
  animation-delay: 4s;
}

.parent {}

@keyframes animation_01 {
  0% {
    opacity: 0
  }
  20% {
    opacity: 1
  }
  40% {
    opacity: 0
  }
  60% {
    opacity: 1
  }
  80% {
    opacity: 0
  }
  100% {
    opacity: 1
  }
}


}

<div class="parent">
  <div class="content1">Here goes content1</div>
  <div class="content2">Here goes content2</div>
  <div class="content3">Here goes content3</div>
  <div class="content4">Here goes content4</div>
  <div class="content5">Here goes content5</div>
</div>