What are 'solutions'?

The dictionary definition of a 'solution' is:
a means of solving a problem or
dealing with a difficult situation
- Collins New Edition English Dictionary

There are many 'problems' in many forms facing people around the world today, and much effort is put into dealing with the effects resulting from 'problems' without getting to their root-causes. This section attempts to show some solutions to root-causes that may address problems for everyone, after all:
'A solution is not a solution if it gives someone else a problem'.

This one line highlights a big issue: is it right for me to do something which may be good for me if it is bad for anyone else? It sounds like a simple problem to solve, but it can become very involved depending on an individual's situation and their understanding of 'right' and 'wrong'. Here is one example:

If I am attacked by someone then they are doing something that is 'good' for them but 'bad' for me, but I have to defend myself, don't I? Where do I draw the line on defending myself? Should I stop when I am doing something that's 'good' for me and 'bad' for them? Should I take revenge in what they've done or tried to do to me?

There are root-causes as to 'why' a person may be attacked in the first place, both for the attacker and the attacked. How the attacked responds will determine the future for both attacker and attacked. If the attacked defends themselves too vigorously resulting in harm to the attacker then the attacker may later seek revenge, escalating the conflict without resolving the reason for the original attack, producing a simple 'spiral' of revenge. How can we get to a point in any difficulty where we understand the real reason for it occurring and respond to it appropriately in a way that will not cause more difficulty for anyone (including ourselves) as a consequence?