Correlation

Correlation:

Introduction:
In statistics, dependence refers to any two random variables or statistical relationship between the two sets of data. Relevance refers to the broad class of statistical relationships involving dependence on any one.
Dependent phenomenon familiar examples include physical stature parents and their offspring, the demand for products and the correlation between the price of the correlation between. Relevance is useful because they can, in practice, can indicate prediction relationship. 
For example, power facilities may have less power requirements and power relationship between the weather based on the moderate day. In this example, there is a causal relationship, because of extreme weather cause people to use more power heating or cooling, however, the statistical dependence is not enough to prove the existence of such a causal relationship 
Form, depending on the case means any random variable probability mathematical independence condition is not met. In loose usage, to refer to the relevant two or more independent random variables any way, but technically it is any relationship between the average of some of the more specialized types.

Defination:

"Correlation is a technique which measure the strength of relation ship between two variables".