You can survey students and graph your findings on a scatter plot and most likely see a strong positive correlation between time studying and grades. That is, the more time studying the higher the grades.You can even go as far as to say that one event causes the other to occur.
Studying causes higher grades, right? Well, that is not always true...
There may be a very strong positive or negative correlation between two events, such as two students growing, but this does not necessarily mean that one event causes the other.
For example, if one student stopped growing that does not mean that the other would stop growing. So, let's make a definition here.
A causal relation between two events exists if the first event causes the other.
Note: This is not always true and often mistakes are made in such fields as science when an assumption is made about a causal relation.
