HTML templating with XSLT may be used to save data, too.
For example, if you build a social network profile page using XSLT, alice.xml and bob.xml can reference the same profile.xsl stylesheet which converts the XML profile data to the rendered HTML page. Since the profile.xsl stylesheet can be cached, whenever a new profile is visited, only the profile data in XML needs to be transferred.
Note that the templating can also be used to save data when rendering a single page. Imagine a Twitter clone that displays a list of tweets. If, hypothetically, 80 characters of Tweet data plus 500 characters of XSL template, produce 250 characters of HTML markup, you only need 3 tweets to start saving data (250x3=750 > 500+3x80=740).
For example, if you build a social network profile page using XSLT, alice.xml and bob.xml can reference the same profile.xsl stylesheet which converts the XML profile data to the rendered HTML page. Since the profile.xsl stylesheet can be cached, whenever a new profile is visited, only the profile data in XML needs to be transferred.
Note that the templating can also be used to save data when rendering a single page. Imagine a Twitter clone that displays a list of tweets. If, hypothetically, 80 characters of Tweet data plus 500 characters of XSL template, produce 250 characters of HTML markup, you only need 3 tweets to start saving data (250x3=750 > 500+3x80=740).