BRAPH consists of three layers, from left to right: Graph, Data Structures and Graphical User Interfaces (GUIs). These layers are connected by unidirectional software interfaces (arrows). Graph contains the functions to perform graph analyses. In Data Structures, Brain Atlas allows defining the nodes of the network, Cohort allows defining the subjects to be studied and dividing them into groups, and Graph Analysis permits building the connectivity matrices and calculating network measures; each of these is implemented in an object, whose functionalities can be called by command line. For each of these objects, a GUI is provided (i.e. GUI Brain Atlas, GUI Cohort and GUI Graph Analysis). Thanks to this architecture BRAPH can be very easily maintained, expanded and customized.