What is the difference between Dynamic & Impact Loading?
The answers given by various people are all fine.
Just make you more comfortable with it, consider the graph of loading(on a structural element, say a beam) vs. time.
In case of dynamic loading, the graph would be a simple curve with no sudden ‘jumps’ or ‘peaks’.
In case of impact loading, this wont be a case. It’s graph is characterized by a ‘peak’ at some time ‘t’. This peak’s magnitude would be significantly greater than at other times.