What is a DBA's definition of "batch"? I've heard it being used in relation to SQLite sometimes but never completely understood what it means.
A batch is a series of SQL commands that are sent to the database server at once. This can be faster than sending each command individually because there is less network communication.

SQLite is an embedded database; SQL commands are executed directly by the SQLite library.
There is no separate server, so it would not make sense to have batches. SQLite does not have such batches.



Another meaning of "batch" might be the multi-row form of the INSERT command:

INSERT INTO MyTable(ID, Name) VALUES (1, 'this'), (2, 'that'), (3, 'whatever');