# What is the difference between horizontal and vertical ensemble?

I am looking at different ways to do model ensembling and I came across the terms horizontal and vertical blending/ensembling but it is not well defined.

My questions will be:

1. What is the difference between horizontal and vertical blending?
2. In which cases which one is better?
3. Are there any python implementations for them?

2. Ensembling can refer to multiple things. Boosting methods can be considered ensembling, since these algorithms are doing intermediate calculations to see what learners are performing better in order to shift weights in the modeling. These methods are built into the algorithms themselves, so I would look into scikit learn and its ensembling methods to get a sense of what's going on. To your specific concern, however, you can look through Github repos for ensemble learning.