Database types and use cases

Databases are where your app stores information. SQL databases organize data in tables, like a phone book: everyone has a name, number, and address in the same format. When you create an account on Amazon, your info goes into neat rows and columns.

NoSQL databases store data in flexible formats, so each record doesn’t have to follow the same structure. For example, one record might have just a name, while another has a name, photo, and favorite color. Instagram uses this flexibility because posts can include photos, videos, or both, and not every post has the same data fields. This makes NoSQL well-suited for applications with varied or evolving data.

Developers choose SQL when you need structure (like tracking orders where every order must have price, date, customer). They choose NoSQL when things vary (like user profiles where some people add bios, some don't). Many apps use both.