Question

The identity template looks like this:

<xsl:template match="@*|node()">
    <xsl:copy>
        <xsl:apply-templates select="@*|node()" />
    </xsl:copy>
</xsl:template>

Does <xsl:apply-templates select="@*|node()" /> select more than <xsl:apply-templates />, or could the identity template have been like this?

<xsl:template match="@*|node()">
    <xsl:copy>
        <xsl:apply-templates />
    </xsl:copy>
</xsl:template>

What exactly is selected when I do the following?

<xsl:apply-templates />

Answer 1

Does <xsl:apply-templates select="@*|node()" /> select more than
<xsl:apply-templates />, or could the identity template have been
like this?

<xsl:apply-templates/> 

is equivalent to:

<xsl:apply-templates select="node()"/>

and this is a shorter former of:

<xsl:apply-templates select="child::node()"/>

and this is a equivalent to:

<xsl:apply-templates select="* | text() | comment() | processing-instruction()"/>

As we see from the last instruction, the xsl:apply-templates instruction you are asking about, doesn’t select any attributes, therefore it cannot be used as a shorthand for:

<xsl:apply-templates select="@*|node()"/>