In what way do the nervous and endocrine systems differ in a way
they communicate messages throughout the body?

The nervous system communicates through electrical impulses and the communication is very fast. It works in a relay fashion, from point to point comparable to the way the old telephones systems used to work.

The endocrine system communicates by chemical signals via the bloodstream. Hormones are secreted into the blood and extra cellular fluids, then transported to target cells, which must bear a receptor to be able to bind to a specific hormone, and respond. 

Hormones are chemical messengers secreted into blood or extracellular fluid that affect the function of other cells.

Endocrine communication is not quite as fast as the nervous system communication