Elastic elongation is the length at which a line will stretch before it can return to its original length. If it’s stretched more than this then it will no longer be able to return to its original length and would have lost its stretch.
Elongation at fracture is the point at which the line has stretched too much and it then snaps. This is usually expressed as a percentage and is a line goes beyond this point then there is no way back and the line would have failed.
Minimal load elongation determines how the line is stretched when it only has to deal with a small number of loads. This will affect the feedback that the fisherman will be able to feel on their line so it can be important for those who love to feel their catch.