What is Firestore?
Cloud Firestore is Firebase's NoSQL document database. Instead of the table/row format, it stores data as Collection → Document → Field. With realtime listeners built in, the UI can update instantly the moment the data changes.
Example structure
userscollection holds user documentsnotescollection holds note documents- A single document can have fields like
title,content,createdAt,ownerId
How it differs from SQL
Firestore has no joins. To keep queries fast, you'll sometimes need to duplicate data on purpose — this is called denormalization. It sounds a bit odd at first, but in the NoSQL world it's basically like serving rice and curry on the same plate instead of separate dishes — a bit unconventional, but perfectly normal here.