Statisticians use correlation and regression analysis to study the relationship between variables in Multi-variate data distribution. Correlation methods are used to determine whether a relationship exists between the variables, while regression analysis provides methods to measure and describe the relationship. The relationship found in Bivariate data sets, that is between the independent and dependent variables is called a simple relationship. The description of a correlation includes the direction, strength and shape of the relationship. The correlation is categorized in terms of direction as:1. Positive Correlation
2. Negative Correlation.

The relationship between the dependent and independent variables when both variables increase or decrease simultaneously is called a positive correlation between the variables.
The Scatter plot drawn will show points clustered in a corridor like pattern from bottom left to top right.
If a fitting line or curve is drawn to represent the pattern of distribution, the slope at any point on the curve is always positive.