Here are just a few of the thousands out there:
Quora saves your history and interests in a database so it can remember the questions and answers you’ve posted. When I click submit on this answer, it will go into a database. When you asked this question, it went into a database.
Facebook saves your data so it knows who your friends are, the posts you have made and liked.
Twitter saves all of your tweets in a database, much like Facebook.
Uber uses databases to keep track of who needs to be picked up, who just got picked up, who needs to be charged how much, and how much to pay each driver, etc.
When you submit the login form, the web server looks up your account in a database and if it finds a matching username and password, then you are authenticated and logged in. While you are using the applications, almost all of your actions are recorded in the application’s database. This is how the application knows what to present to you on the screen, what to recommend to you next, or otherwise present the features that the application was developed to deliver.
The SQL Server is a relational database management system from Microsoft. The system is designed and built is to manage and store information. The system supports various business intelligence operations, analytics operations, and transaction processing.
C# is a programming language. C# can be used to create a number of different programs and applications: mobile apps, desktop apps, cloud-based services, websites, enterprise software and games. Lots and lots of games.
Python is a widely-used, interpreted, object-oriented, and high-level programming language with dynamic semantics, used for general-purpose programming.