CQL3 (the Cassandra Query Language) provides a new API to work with Cassandra. Where the legacy thrift API exposes the internal storage structure of Cassandra pretty much directly, CQL3 provides a thin abstraction layer over this internal structure. This is A Good Thing as it allows hiding from the API a number of distracting and useless implementation details (such as range ghosts) and allows to provide native syntaxes for common encodings/idioms (like the CQL3 collections as we’ll discuss below), instead of letting each client or client library reimplement them in their own, different and thus incompatible, way.
CQL seems to be the solution Cassandra is using to address the sometimes confusing or complex data model. I also think that CQL is an attempt of bringing Cassandra closer to SQL-enabled tools, a feature that might allow more integrations in the future.
Original title and link: Cassandra Query Language CQL3 Explained (NoSQL database©myNoSQL)