Some universities that offer a DSc as the doctoral degree, while most of them also offer a PHD degree in science. What are the differences these degrees in terms of academic standing? What are the pros and cons?
It depends on the university and the country.
In England, a PhD is typically awarded for a thesis and oral examination of the thesis, usually followed by implementation of corrections to the thesis, the requirements for which are specified during or just after the oral exam. It's often done soon after a Masters, which is done soon after a Bachelors, so a fairly large proportion of PhDs are awarded at the start of one's academic career. Whereas a DSc is awarded for a portfolio of work, (in some cases submitted together with an over-arching critique of that portfolio), and thus is more likely to be awarded later in an academic's career.
Nominally, a PhD is a doctorate in philosophy, but is typically awarded for pretty much any subject. There are some who argue that philosophy of knowledge always form part of these studies, regardless of the subject. I occasionally use this line to try to inspire students, myself. A DSc is a doctorate in science, and is not awarded for literature, law, divinity, or music, each of which has its own dedicated higher doctorate.
The DSc is a higher doctorate than a PhD, in England. In some other countries, they're equivalent.
Both get the honorific title doctor.
A good summary of the differences between Ph.D. and the "Doctor of Science" family of degrees (D.Sc./Sc.D./etc.) can be found in Wikipedia.
In essence, different countries have different views due to their historical development, which generally fall into two clusters:
- Doctor of Science is equivalent to Ph.D.
- Doctor of Science is a sort of super-Ph.D.
In general, much of the world seems to be slowly standardizing around Ph.D. as a universal term, though given national pride and the traditions of academia, it might never congeal completely around a single interpretation of the terms.
In the United States, the Doctor of Science is identical to the Doctor of Philosophy except that it's awarded only in the natural sciences, and only by a few universities. Massachusetts Institute of Technology awards both degrees, for instance, and the curriculum is identical. (MIT doctoral graduates in the physical sciences and engineering can choose either degree title once all the requirements have been met. Those in the social sciences and biology don't have the option of choosing the Doctor of Science, however; they all get the PhD.)
In the United Kingdom and some other countries, the Doctor of Science is a "higher doctorate" awarded after submission of a portfolio of published work -- typically around 80-120 journal articles. It signifies a much higher level of accomplishment than the PhD, and it's usually awarded to researchers relatively late in their careers. There are equivalent higher doctorates in other fields of study: Doctor of Letters, Doctor of Laws, Doctor of Divinity, etc.
The Doctor of Science Degree is purely a research degree that extends well beyond what is formally required for a Doctor of Philosophy Degree. Extensive publication of research is a prime prerequisite for the D.Sc. Degree, not merely the completion of a dissertation. A dissertation plus an extensive port folio of research publications add-up to qualify a candidate for the Doctor of Science Degree. Usually the D.Sc. Degree is inter-disciplinary, such as a combination of research in history, economics, and political science or government, which gears the candidate for inter-disciplinary publication.