ANISOTROPY MEANS TO CONCENTRATE ITS PROPERTY AND FLOW IN A PARTICULAR DIRECTION WHILE IN ISOTROPY PROPERTIES AS WELL IS FLOW OF CHARGED PARTICLES IS UNANIMOUSLY DISTRIBUTED IN ALL THE DIRECTIONS.
Anisotropy implies different properties in different directions, whilst isotropy implies the same properties in all directions. The following two freely downloadable PDFs will be useful.
[1] "ISOTROPY/ANISOTROPY IN GALACTIC COSMIC RAYS: SOURCES AND MAGNETIC FIELDS" by Dr. Elena Amato