css show another element when hover code example

Example 1: on hover display another div css

.showme {
  display: none;
}

.showhim:hover .showme {
  display: block;
}


<div class="showhim">HOVER ME
  <div class="showme">hai</div>
</div>

Example 2: css hover change other element

#container:hover > #cube { background-color: yellow; }