Compassion, empathy, or sympathy are like close cousins. The three of them do carry different meanings but are very much related to each other, and this is the reason why people use these words for the same purpose. These three can be defined as the stages. The first stage is sympathy, which means to understand the problem/suffering, the second one is the empathy it means to be able to feel the pain, and the last one is compassion, which says, having enough courage to provide the solution.
What is compassion?