A deterministic model is one where outcomes are exactly determined through known relationships, without random variation, and a specific input always produces the same output, as seen in classical physics models. Statistical models, which econometrics is more interested in, involve stochastic relationships. Regression analysis examines the dependence of one variable on others, but dependence does not imply causation, which can only be plausibly claimed under certain conditions. Cross-sectional data involves many units observed at a single point in time, time-series data tracks a single unit over multiple times, and panel data follows multiple units over multiple times.