Correlation is a statistical calculation that indicates in which the two variables are parallelly related (which means that the variables change together at a constant rate). Itâ€™s a simple and popularly used tool for defining relationships without delivering a statement concerning the cause and effect. In simple words, correlation is a statistical calculation that estimates the point at which the two variables shift in relation to each other.
A positive and perfect correlation indicates that the coefficient correlation is exactly 1. It indicates that when one variable moves upward or downward, another variable move is structured in the same direction. However, a negative and perfect correlation indicates that both the variables move in opposite directions. When there is a zero correlation, it means there is no relationship at all.
Different Types of Correlation
(A) MEANING OF CORRELATION 

(B) TYPES OF CORRELATION 

Q.1 If a change in the value of one variable accompanies/causes a simultaneous change in the other variable in the same or opposite direction, it is termed as ______________. 
a. Range b. Dispersion c. Correlation d. Variation 
Q.2 How many types of correlation are there? 
a. 4 b. 5 c. 2 d. 3 
Q.3 Which of the following is not a type of correlation? 
a. Positive Correlation b. Negative Correlation c. Simple Correlation d. None of the above 