Mysql and PostgreSQL are the two most popular SQL databases. They have many differences, some of them are:-

1. Mysql is a popular database, whereas PostgreSQL is the most advanced Database.

2. Mysql is relational-based based, whereas PostgreSQL is an object-based relational database.

3. Mysql supports basic data types, whereas PostgreSQL supports advanced data types.

4. Mysql does not support Materialised views, whereas PostgreSQL supports Materialised views.

5. Mysql has limited MVCC support, whereas PostgreSQL has Full MVCC support.