Edit in JSFiddle

 @keyframes left_move {
   from {left: 0px;}
   20%  {left: 200px;}
   60%  {left: 50px;}
   75%  {left: 100px;}
   to   {left: 0px;}
 }

div {
   width: 100px;
   height: 32px;
   margin-top:5px;
   background: pink;
   position: relative;
   animation-name: left_move;
   animation-duration: 5s;
   animation-iteration-count: infinite;
}
 
 .ex1 { 
   animation-timing-function:linear;
 }
 .ex2 { 
   animation-timing-function:ease;
 }
 .ex3 { 
   animation-timing-function:ease-in;
 }
 .ex4 { 
   animation-timing-function:ease-out;
 }
 .ex5 { 
   animation-timing-function:ease-in-out;
 }
<!DOCTYPE html>
<html lang="ko">
  <head></head>
  <body>
    <div class="ex1">linear</div>
    <div class="ex2">ease</div>
    <div class="ex3">ease-in</div>
    <div class="ex4">ease-out</div>
    <div class="ex5">ease-in-out</div>
  </body>
</html>