Cool image from http://learn.panoply.io/
To save words and time, a table is presented for you to clearly skim through the differences between a relational database (e.g. MySQL) and a non-relational database (e.g. MongoDB). There are 10 features of both types of databases are compared to provide you a high-level understanding about their distinctions.
Table of Comparison: Relational versus Non Relational Database
Two great references are suggested for you to dive deeper into this: