ORMs reduce raw SQL and help model relationships, migrations, and queries in application code. They speed up common work but can hide expensive queries if used blindly.
ELI5
Think of ORM as a labeled box where an app keeps important things. A library that lets code work with database records through objects or typed APIs.
In practice
Use it when a feature reads, writes, migrates, validates, or audits stored information. In practice, define the owner, input, output, and failure mode before you rely on it.