dhruv's wiki

Intro

SQLAlchemy Core VS ORM

The two modes use slightly different syntax, but the biggest difference between Core and ORM is the view of data as schema or business objects. SQLAlchemy Core has a schema-centric view, which like traditional SQL is focused around tables, keys, and index structures, making it a good contender for applications like data warehousing, reporting, etc.

ORM is much more suited for domain-driven design.