kde plot for interpreting the correlation
CoreyLevinson on kaggle answered my question. I am simply adding the explaination.

The kde shows the density of the feature for each value of the target. There are usually 2 colored humps representing the 2 values of TARGET. If the humps are well-separated and non-overlapping, then there is a correlation with the TARGET. If the humps are overlapping a lot, then that means the feature is not well-correlated with the TARGET, because the TARGET is equally as common on those values of the feature.