I don't understand what exactly is the difference between "in-sample" and "out of sample" prediction? An in-sample forecast utilizes a subset of the available data to forecast values outside of the estimation period. An out of sample forecast instead uses all available data Are these correct ?
Very specifically is the following definition correct ?
A within sample forecast utilizes a subset of the available data to forecast values outside of the estimation period and compare them to the corresponding known or actual outcomes. This is done to assess the ability of the model to forecast known values. For example, a within sample forecast from 1980 to 2015 might use data from 1980 to 2012 to estimate the model. Using this model, the forecaster would then predict values for 2013-2015 and compare the forecasted values to the actual known values. An out of sample forecast instead uses all available data in the sample to estimate a models. For the previous example, estimation would be performed over 1980-2015, and the forecast(s) would commence in 2016.