How do the processes of basal slip and internal plastic flow differ?

Basal slip involves the movement of crystal planes over each other in a preferred direction, usually parallel to the basal plane, allowing for plastic deformation in materials like metals. Internal plastic flow refers to the movement of dislocations within the material, leading to permanent deformation without fracture. While basal slip is more common in crystalline materials with well-defined crystal structures, internal plastic flow can occur in various materials with defects and dislocations.