What is the significance of repeated DNA sequences?

Question

What is the significance of repeated DNA sequences?

Answer 1

Repeated DNA sequences like mini/micro satellites are also useful for DNA fingerprinting like paternity testing

Answer 2

There are lots of different repeated DNA sequences.  Some are thought to be "dead" viruses that infected cells, some are thought to be due to "slipping" of DNA polymerase during replication, etc.

I'm not sure what you mean by "significance."  I suppose one thing that is significant is that some of these repeats can "move around" the genome.  They can be excised from the genome and insert into a different location in the genome.  If they happen to land in the middle of an essential gene, it could lead to cancer or some other disorder.