What is "time-dependent evolution of the complex noncovalent interaction networks" and why this is important?

From [Maximilian Scheurer, Peter Rodenkirch, Marc Siggel, Rafael C. Bernardi, Klaus Schulten, Emad Tajkhorshid and Till Rudack Biophysical Journal, Volume 114, Issue 3, 577-583](http://www.cell.com/biophysj/pdf/S0006-3495(17)35051-8.pdf):



> 
> One of the most relevant molecular properties that can be investigated
>  by all-atom MD simulations is the time-dependent evolution of the complex noncovalent interaction networks governing
>  such fundamental aspects as molecular recognition, binding strength, and mechanical and structural stability. 
> 
> 
> 


What are noncovalent interaction networks? And why their time evolution is important in structural biology. I tried also to use the authors' library [pycontact](https://github.com/maxscheurer/pycontact), but it's not clear to me how to use it. 


