Univariate data:

Univariate data is defined as a data, which consists of one variable under study.

Bivariate data:

Bivariate data is defined as a data, which consists of two variables under study, simultaneously.

Multivariate data:

Multivariate data is defined as a data, which consists of more than two variables under study, simultaneously.

Consider a data set with n individuals.

Suppose that only one characteristic of each individual is studied. Then, the data would record only one variable for each sampled individual. In this case, the data would be a univariate data.

Now, suppose that two characteristics of each individual are studied simultaneously. Then, the data would record two variables for each sampled individual. These two variables would be dependent on each other, as they are collected from the same individual. In this case, the data would be a bivariate data.

Again, suppose that three or more characteristics of each individual are studied simultaneously. Then, the data would record three or more variables for each sampled individual. These variables would be dependent on each other, as they are collected from the same individual. In this case, the data would be a multivariate data.

Univariate data is defined as a data, which consists of one variable under study.

Bivariate data:

Bivariate data is defined as a data, which consists of two variables under study, simultaneously.

Multivariate data:

Multivariate data is defined as a data, which consists of more than two variables under study, simultaneously.

Consider a data set with n individuals.

Suppose that only one characteristic of each individual is studied. Then, the data would record only one variable for each sampled individual. In this case, the data would be a univariate data.

Now, suppose that two characteristics of each individual are studied simultaneously. Then, the data would record two variables for each sampled individual. These two variables would be dependent on each other, as they are collected from the same individual. In this case, the data would be a bivariate data.

Again, suppose that three or more characteristics of each individual are studied simultaneously. Then, the data would record three or more variables for each sampled individual. These variables would be dependent on each other, as they are collected from the same individual. In this case, the data would be a multivariate data.