Data is the plural form of the Latin datum (a “given” fact).
In scientific research, data arise from experiments whose results are recorded system
In business, data usually arise from accounting transactions or management processes.
Observation – each data value
Subject (or individual) – an item for study (e.g., an employee in your company).
Variable – a character about the subject or individual (e.g., employee’s income).
univariate - Histograms, descriptive statistics, frequency tallies
bivariate - Scatter plots, correlations, simple regression
multivariate - Multiple regression, data mining, econometric modeling
A data set may have a mixture of data types.