# Understanding Data Modeling in PowerBI: Joins, Relationship and Schemas.

Introduction. Data Modeling is a good backbone of making Data Science and Analytics in PowerBI very successful. We are going to look into: Data modeling fundamentals. SQL Joins. PowerBI relationships. Facts vs deimension tables. Data schema. The big Question; WHAT is data modeling. Well Data modeling is the process of organizing and structuring data from multiple sources into a logical format for analysis. Here it is all about: The Table connection. Defining relationships. Structuring data into facts and dimension tables. Optimizing performance. Just imagine all this like making your data easy and smooth to read and interpret. SQL joins. This is basically where we use joins to make data jointed from multiple tables using a common column. 1. INNER JOIN. This only returns matching records in both tables. 2. LEFT JOIN. Here in the records are all returned from left side of the table and matching the records from the right. 3. RIGHT JOIN. This is basically the vice versa of LEFT JOIN, the