It's generally understood there are two kinds of database administrators, production and development, but the definition of each kind is not universal. If the difference were simply their environments (production or development) then there would be no need to distinguish between them. I would like to propose a definition with a very clear distinction. A production DBA is concerned about everything outside the database. A development DBA (database developer) is concerned about everything inside the database.

A production DBA considers a database to be the smallest item on which to focus. A production DBA handles storage space, database maintenance, disaster recovery, high availability, replication, log shipping, mirroring, logins/users, SQL Server Agent jobs, performance monitoring, and maybe some performance tuning. The primary point of focus is a server or a SQL Server instance. A production DBA has very little need to understand how the business works.

A development DBA considers a database to be the largest item on which to focus. A development DBA handles data modeling, normalization, table structure, DRI, indexes, data types, naming conventions, triggers, stored procedures, views, functions, code generation, data import/export, archiving, purging, and auditing. The primary point of focus is a database or a set of databases. A development DBA (database developer) must understand how the business works.