SQL or Standard Query Language is a computer programming language that was developed in order to get, update and delete data from a data management systems.
SQL is used by intermediaries and other companies that support E-Commerce businesses in order to collect, process, and retrieve data from common customers. This data is often collected via e-mail, or optional forms filled out by the customer, and is compiled and processed into the data management database. SQL is the language that reads this information, and gives the business the collected information. Information that they can then use in order to alter their business communications, advertisements, etc. to better suit their clients.