W elcome Back Readers !, For those who have not read the previous post on How Machine Learning works ? Please do read previous one before continuing this so that it would be more easy to understand. You can find the previous post here How Machine Learning Works ? - Mathematics Every Where . For other who are ready to join with me in this journey to understand the Machine Learning, Thank you for being with this post. Till now we are discussing on the the title "How Machine Learning works? " and to understand that we have seen in the first post that there exist the patterns or trends in the data and we try to find that in terms of a mathematical equation called a model and try to fit to the new data that we have not came across for predicting the values. Wow may be we got the entire process complete with this. But there are few thinks that needs to be cared while training the model or creating the model or while processing the data for the model creation.