What is a Database?

Databases or databases are sets of files related to each other with records about people, places or things.
They are organized collections of data that are related in order to create some sense (Information) and give more efficiency during research or scientific study.
Databases can be relational or non-relational.

Relational:

Each table in a relational database contains one or more data in columns, and each row, also called a record, contains a unique data instance or key to the data defined by the columns.
Each table typically has a primary key column, a unique record within the table to identify the records.
Relationships between tables can be defined through the use of foreign keys – a field in one table that links to the primary key in another table.
Relational databases useSQL.

Non-Relational:

There are several types of non-relational database, they are categorized by their way of storing data.
The two most used types of NoSQL databases are:

Document Database:

It stores its data in documents similar to JSON objects (JavaScript Object Notation).

Key-Value:

They are a more “simple” type of database, where each item contains keys and values.
These values can be any type of data, a text, a number, a JSON and they can be retrieved by referring to your key, making your query very simple.
These databases are great for when you need to store large amounts of data, but don't need to run complex queries against them.
The most common uses are for caching data.
Redis and DynamoDB are probably the most popular databases of their kind.