There are many definitions, but this is a pretty good one for business scenarios.
“A conflict of interest occurs when an entity or individual becomes unreliable because of a clash between personal (or self-serving) interests and professional duties or responsibilities. Such a conflict occurs when a company or person has a
vested interest, such as money, status, knowledge, relationships, or reputation, which puts into question whether their actions, judgment, and/or decision-making can be unbiased. When such a situation arises, the party is usually asked to remove themselves, and it is often legally required of them.”
It was something that we were hot on and mostly very good at in my former professional services industry, but that so many in the investment industry seem to continue to struggle with