Look I have this code:  
CSS:

```
<style>
span#logo {
    height: 80px;
    width: 222px;
    background: url(img/logo.png);
    /* If I take out this it would give my span 0x0px size */
    float: left;
}
</style>

```

HTML:

```
<span id="logo"></span>

```

Why does it happens? Why do I need to have the float for it to have shape?