Why does the vertical-align vertical center function and textalign vertical center?

Why does the vertical-align vertical center function and textalign vertical center?

Why does the vertical-align vertical center not work:

Vertical-align attributes may not be used too frequently, but sometimes vertical-align: middle may be used to set vertical center alignment of elements inside the object, however, sometimes this setting does not produce results. The code example is as follows:

<! DOCTYPE html> 
From the code above, we can see that the vertical-align attribute takes effect. Let's take a look at the example code:
<! DOCTYPE html> 
The above Code shows that the vertical-align attribute does not work. This is because this attribute can only be applied to elements with the valign attribute. The table element has the valign attribute, but the div element does not. In the second example, the vertical-align attribute does not work.
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