A database is an organized collection of structured information stored electronically. It lets you store, retrieve, and update data efficiently. A phone contact list is a simple database. A bank's transaction records are a complex one. The software that manages it is called a database management system, or DBMS.

Relational databases organize data into tables with rows and columns. SQL is the standard language for querying them. NoSQL databases handle unstructured data like documents, graphs, and key-value pairs. Each type suits different needs.

Core operations

• Create: insert new records
• Read: query existing data
• Update: modify records
• Delete: remove data
• Index: speed up searches

Databases are everywhere. Your bank, your hospital, your streaming service, and your government all run on them. They must be fast, reliable, and secure. A corrupted database can bring an organization to its knees. Backups are not optional.