There are some people who may get confused with these two. Idealism is a situation wherein you would see things in a more ideal manner. This means that whenever you think of scenarios, you imagine the outcome to be the best at all times. Realism, on the other hand, would require thinking about what is actually happening.
This means that the things that may happen will depend on so many factors such as the fact that there are situations that cannot be controlled. There are thoughts, ideas, and other things that would need to be considered to know what the possible outcome might be within a given time frame.