Short answers, pulled from the story.
The Old Norse name Sköll carries the weight of treachery or mockery. Rudolf Simek confirms this meaning in his 2007 work on Northern mythology while Andy Orchard notes it in his 1997 Dictionary of Norse Myth and Legend.
Snorri Sturluson recorded the story of Sol driving her chariot across the heavens in his Prose Edda during the description of the Sun. The text states there is nothing she can do but flee from the wolf named Skoll who pursues her at a great pace.
The prophecy foretells that the wolves will chase the Sun and Moon until Ragnarök arrives at the end of the world. At that final moment, Sköll specifically devours the Sun goddess Sól when no escape remains once the chase concludes its long duration.
Rudolf Simek proposed that Sköll might be another name for Fenrir himself suggesting these three figures could be one and the same entity in different contexts. He suggests these three figures could be one and the same entity in different contexts where Sköll and Hati are sons of the wolf Fenrir and an unnamed giantess.
Nature-mythological theories link the wolves to parhelia and paraselenae phenomena which appear as Sun dogs or Moon dogs in Scandinavian languages. Rudolf Simek theorizes the wolves derive from the Hyades star cluster within Taurus forming a V shape that resembles the open mouth of a wolf.