Econometrics is essentially the application of statistical methods to economic research and modeling.
Select concepts and methods include:
Instrumental variables
Exogenous and Endogenous variables
Time series methods
Regression (OLS, MLE, robust)
Loglinear models
Poisson and Negative Binomial models
Models based on Panel Data
Duration models based on survival functions
Analysis of financial data
Reasonably good econometric references start with:
A Guide to Modern Econometrics (Verbeek) for methods of econometric analysis.
The Secrets of Economic Indicators (Baumohl) for economic indicators, their definitions, and where to find them.
References for related methods include: