Non-blocking means operations do not obstruct the execution flow.
In reactive programming, non-blocking means that operations, such as I/O, are designed to not halt the progression of other processes. This is essential for high-performance applications. For example, in an e-commerce server, while waiting for a database query, the server can still handle other requests without waiting for the query to complete.
Additional Notes
What does ‘non-blocking’ mean in reactive programming?