Here's a quick little overview.
- Dynamic Generation
The word 'dynamic' means changing. The word 'generation' means creation of things therefore 'dynamic generation' is changing generation. Therefore 'dynamic generation' refers to content that is constantly changing.
- Procedural Generation
The word 'procedural' refers to content created by a computer algorithm and not a human. As we established 'generation' means creation so therefore 'procedural generation' refers to content which are generated via a computer algorithm.