Relational Databases
RelationalDatabases refers to databases in which we store data in the form of tables, often referred to as Relations.
Each table has a column dedicated to uniquely identifying each row in that table, using a unique non repeating (within that table) value referred to as a PrimaryKey. Therefore a table can have a column that stores the primary key of corresponding (related) rows in another table, thus creating a relationship between both tables.
This is extremely helpful for storing data on pretty much anything, to a certain degree of accuracy and/or realism. The conversion of real things and their properties to relational data models, known as RelationalSchema is never a perfect 1:1 conversion that captures the entire essences of our discourse, commonly referred to as UniverseOfDiscorse (UoD).
Structured Query Language
SQL is a database query language that allows us to conduct CRUD (Create, Read, Update, Delete) operations on such databases. There are various flavors of SQL out there, and while most are the same and share a great deal of syntax and purposes, frankly for the average joe coder they’re interchangeable until they’re not, some have a few differences and added features and capabilities.