Why are pdf files so small? No fonts embedded?

When I compare the file size of the pdf files created with PdfCreator with the
pdf files created with other pdf drivers then there is a significant size difference.

Pdfcreator pdf files are sometimes approx. only 30% of the sizes of other pdf files (with same content of cause).

Why is Pdfcreator so much better?

I could imagine that Pdfcreator does NOT embed used fonts into the result pdf file.
Or alternatively replace unusual fonts with default fonts.

Is this true?

How can I control wether all fonts should be embedded in result pdf or not?