Help on Core Concepts Confusing

[Rut ham cau Quang Hong]

1. what is the differences between connection and a thread?
2. when people say DB supports connection pooling does connecting pool size and thread are same?
3. why JDBC is a blocking I/O and R2DBC claims non-blocking which don't understand
4. pool of connection vs pool of threads

Need one or 2 practical example. If anything with image/diagram would be very much useful.

Thanks.

[Jeanne Boyarsky]

A Connection connects to the database. Threads have nothing to do with databases and are used so you can execute code in the background.

I recommend reading Oracle's Trail on Threads. Understand that before trying to understand JDBC.