Here's the quick definition:
Max Effort is lifting a maximal weight (90-100% of your 1 rep max) for a given rep range, usually 1 to 3 reps. This is usually done to a PR or for reps in the 90% range to build absolute strength.
Dynamic Effort is lifting a submaximal weight (40-60% of your 1RM) with maximum force. This is to help develop speed and to push through sticking points. This is typically done for 1 to 3 reps depending on the exercise: DL-1 rep, SQ-2 Reps, BP-3 reps, and numerous sets, 8-10. This can also be done with bands and chains to help acommodate resistance.
For more detailed description see article above.