Help needed for the term Backorder

[Deviatore]

hey i was surfing a site when i found some deleted domains...i saw many were worthy so i searched from them in godaddy but i found a term "Backorder"
Can anyone help me with this term?
Is it necessary if i want to take it before someone else takes it?

[k3v]

To register expiring domain you must use drop catching services,i recommand Pool and Snapnames for domain backorder and not godaddy.