SQL, which stands for Structured Query Language, is a programming language for communicating among databases. The use of queries allows databases to be linked through a management system. The language was developed as a means of communication for people who had to process and send a lot of information. SQL proved to be too complex and for this reason it is now only used to communicate among databases.

SQL comes in different sizes, there are small databases that can be called with a small SQL code. A website or blog for personal use is a good example of this. For larger database queries, a lot of code is required, these connections are mainly used by large companies, businesses and schools. This is the main way data is kept up to date and managed. Consider, for example, the administration of students and managing the suppliers of school supplies. For large companies this can mean the import and sale of goods, or logistic processes.

Connecting databases through programming in SQL has been included in training and educational programs by large enterprises like Microsoft. As a starting point of learning computer science, understanding SQL queries are covered as they occur frequently when setting up an application.