The ranking is done by Cybermetrics Lab, a research group belonging to the largest public research forum in Spain, Consejo Superior de Investigaciones Cientificas (CSIC). It is done on three criteria – online impact/visibility (online connections of other universities to the online presence of the analysed university), citations in the GoogleScholar system, number of articles included in the top 10% of the most cited articles, in 26 fields of science, in the reference index.

The entire ranking of Romanian universities can be consulted here.
 
The evolution of “Dunarea de Jos” University of Galati in this ranking is a spectacular one for the last years. If in 2018 the university occupied the position 2,204 in the world, and in 2019 it was on the 2,245 position, in 2020 the university climbed on the 2,061 position, and in January 2021 it reached the 1,966 position.
 
According to the website’s data, other 25 higher education institutions from Romania occupy different positions between 2000-5000, 18 between 5000-10,000, 10 on the 10,000-15,000 places, 27 on the 15-20,000 places, and another 10 on the 20,000+ places.