Corruption may be viewed from the point of view of a private individual/person. It could be the fraudulent acquisition of a good, it may be taking and/or doing an illegal advantage of an opportunity for a position, contrary to the objective underlying the opportunity or the position or seeking a private gain at the loss of an individual or a group.
Corruption from the perspective of the private sector: an established business that belongs to a determinate people where someone takes advantage of what is expected or supposed to be beneficial to a group and personalise group benefit.
Corruption from the perspective of public sector level: Commercial/economic or political view. This refers to people occupying public offices in the public services, executive, judicial or legislative house. Corruption then means taking advantage of opportunities unfairly of other persons.
We can then be more specific in defining corrupt practices. However, the more specific, the more entangled it will be. Corruption is not about money, but about value. It is an exchange of something for something. It is an attempt to take advantage of another person. The phrase “using what you have to get what you need” underlies corruption.
In some cases, corruption may be a victimless crime. Such is money for a grade, but the system itself is the victim.