问>和空间有什么区别？

EN

a
  c
  b
    c
  d
    c

<style>
.element1 .element2{ 
    color: #2196F3;
    background-color: #FFEB3B;
}
</style>

<div class="element1">
    <p class="element2">
        As you can see that this paragraph with class `element2` is inside div with class `element1` and so it's catched by css written above.
    </p>
</div>

<style>
.element1 > .element2{ 
    color: #2196F3;
    background-color: #FFEB3B;
}
</style>

<div class="element1">
    <p class="element2">
        This paragraph is catched by css above because this paragraph with class `element2` is immediate child of div with class `element1`.
    </p>
</div>

<!--no effect-->
<div class="element1">
   <div class="middleelement">
      <p class="element2">
          This paragraph is <strong>NOT</strong> catched by css written above because it's not immediate child of div with class `element1` because class `middleelement` comes in between. To refer to this paragraph, you have to write css as `.element1 &gt; .middleelement &gt; .element2`
      </p>
   </div>
</div>

a
  b
    c
  d