Question: For the longest time I was styling my elements in this way.

```
table .class tr, th{

} 

```

Today I had some insane css related bugs and it occurred to me that it may have worked in the past by accident and in fact what it is doing is not selecting tables of a certain class but selecting tables followed by elements of a certain class.

I kind of assumed that css would just ignore the space between table and .class. But does it?

```
table.class tr, th{

} 

```

Would this work differently? I can't believe I didn't think about this before! (embarrassed)

Thanks!

Answer: 
You answered it in your question:

`table .class tr, th`... selects a `tr` inside a `.class element` inside a `table` **and** a `th`.

`table.class tr, th`... selects a `tr` inside a `table with the class "class"` **and** a `th`.

The space makes a difference.

With the space, you are selecting another element in between the `table` and the `tr` (perhaps a `thead` or `tbody`?)

Without the space, you are selecting a `table` with the class `class`.

BTW, I am not sure you want this, but the `, th` means *"also give these same styles to all `th`s"*.
`table .class tr` would select a `tr`:

```
<table>
  <tbody class="class">
    <tr></tr>
  </tbody>
</table>

```

but nothing:

```
<table class="class">
  <tr></tr>
</table>

```

While `table.class tr` would select a `tr`:

```
<table class="class">
  <tr></tr>
</table>

```

AND a `tr`:

```
<table class="class">
  <tbody>
    <tr></tr>
  </tbody>
</table>

```

But nothing:

```
<table>
  <tbody class="class">
    <tr></tr>
  </tbody>
</table>

```