Ensemble Machine Learning in Python : Adaboost, XGBoost

Let's say you want to take one of the very important decision in your life, it will be a choosing your career or choosing your life partner. Do you think that you can depend on a just one person advice. Advice from the one person can be highly biased also. The best way you can go ahead by asking and taking guidance from multiple people which reduce the bias. Same thing apply on machine learning world also while predicting some class or predicting any continuous value for regression problem, why you should rely on a one model only.