What is Database? According to the course, the database is not only a collection of information data, but it also an interface to interact with data such as add new data, remove data, or edit data. Two Broad Categories of Database: SQL (sequel) SQL is also called relational database. Sequel database are tabular database which data is stored in a table. From Google Image NoSQL(non-sequel) For NoSQL, they are no tables, and it is basically JavaScript objects with a bunch of key value pairs. What's the difference between SQL and NoSQL? SQL has been around the longest. When we mention database, most people include myself first think of table. Everything is tabular, and if we want to relate data, we have to build other tables to relate that data. However, NoSQL is non-relational database, so we don't have to define any tables and patterns. This is a much more flexible structure. The course also mentioned that flexible structure is bette...