Big companies around the globe are using NoSQL Databases to provide the velocity that the users expect when using their applications; companies such as Facebook, Amazon, and Google all use them. However, why are these databases so special? To answer this question, let's see what is the difference between SQL and NoSQL databases:
| SQL databases | NoSQL databases |
| Table-based and hard structured | Not table-based |
| Encourage normalization | Encourage denormalization |
| Require a schema | Are schema-less |
| Fast | Superfast |
| Scalability is difficult to achieve | Scalability is extremely easy to achieve |
Of course, there are more differences and benefits, but talking about all the advantages and the science behind them is beyond the scope of this book.
It is important to know that there are different types of NoSQL databases to solve different types of challenges. Let's learn about them.