.el {
  width: 50px;
  height: 50px;
  background: rebeccapurple;

  animation: 
    1s one infinite alternate ease,
    1s two infinite alternate ease;
}

@keyframes one {
  from {
    transform: translate(0, 0)
  }
  to {
    transform: translate(0, 100px)
  }
}

@keyframes two {
  from {
    transform: translate(0, 0)
  }
  to {
    transform: translate(100px, 0)
  }
}