What is the difference between line to line and ground to line faults?

A new mechatronics study program is created within existing mechanical, 

electrical and/or computer engineering departments. The study program is a 

combination of existing and newly developed courses and one or more persons 

coordinate the study 

A line to line fault  is the Short Ciruit happen between two phases of the system

A line to ground  fault is the Short circuit happen between one  phase of the system  and the earth