NoSQL is a fast, portable, relational database management system without arbitrary limits. It runs under, and interacts with, the UNIX operating system. It uses the Operator/Stream DBMS paradigm. There are a number of "operators" that each perform a unique function on the data. The "stream" is suplied by the UNIX input/output redirection mechanism. Therefore each operator processes some data and then passes it along to the next operator via the UNIX pipe function. This is very efficient as UNIX pipes are implemented in memory. NoSQL is compliant with the relational model.
