Put simply, ranking refers to an international evaluation practice that measures universities' performance on a wide range of criteria or benchmark indicators.
The participating universities are ‘awarded’ with points according to how well they meet these criteria. The universities are then ranked according to their score. Rankings can therefore in many ways be described as an international tool for comparing higher education institutions.
The ranking of universities was originally created with the purpose of measuring research quality, but today the various rankings cover a much broader focus within both research and educational quality as well as daily operations, but also environmental development and sustainable change.
Typically, the ranking task is handled by international organizations and many of the more classic rankings are rooted in research publication journals or databases. However, there are also other kinds of ranking players, for example the universities themselves.
Thus, there are many other types of rankings and ranking agencies, each of which has its own origin, area of focus, and associated methods to ranking of universities.