It addresses the problem of theodicy, meaning why God permits evil in the world, through the experiences of the eponymous protagonist.
Job is a wealthy and God-fearing man with a comfortable life and a large family; God, having asked Satan for his opinion of Job's piety, decides to take away Job's wealth, family and material comforts, following Satan's accusation that if Job were rendered penniless and without his family, he would turn away from God.
Scholars generally agree that it was written between the 7th - 4th centuries BCE, with the 6th century BCE as the most likely period for various reasons. The anonymous author was almost certainly an Israelite, although the story is set outside Israel, in southern Edom or northern Arabia, and makes allusion to places as far apart as Mesopotamia and Egypt.
The rest of this comprehensive Wikipedia article on the book can be readhere.
An extract from BHFA Volume 5
אָח הָיִיתִי לְתַנִּים וְרֵעַ לִבְנוֹת יַעֲנָה׃
an ostrich to daughters of and a companion to ostriches I am a brother
KJB I am a brother to dragons, and a companion to owls.
NASB I have become a brother to jackals And a companion of ostriches.
ESV I am a brother of jackals and a companion of ostriches.
NLT Instead, I am considered a brother to jackals and a companion to owls.
NIV I have become a brother of jackals, a companion of owls.
לְתַנִּים is often seen as an erroneous form of תַּנִּין meaning, "serpent, dragon, sea-monster." However, from many instances like Mi 1:8 and Is 13:22 it clearly means a well-know bird namely the ostrich, known for its mournful howling.
Refer to Hattingh, Tian (2012), Birds and Bibles in History, p. 96 for a discussion of all the texts in the Hebrew Bible where ostriches are mentioned.
and feather stork pinion but wave proudly ostrich the wings of
NIV The wings of the ostrich flap joyfully, though they cannot compare with the wings and feathers of the stork
NLT The ostrich flaps her wings grandly, but they are no match for the feathers of the stork.
ESV The wings of the ostrich wave proudly, but are they the pinions and plumage of love?
KJB Gavest thou the goodly wings unto the peacocks? or wings and feathers unto the ostrich?
NASB The wings of the ostrich flap joyously, With the pinion and feathers of love,
The Hebrew verb רָנַן means, "to give a ringing / complaining / distressing / mourning cry." The m. pl. noun רְנָנִים then literally means, "ringing (etc.) cries."
This distinctive feature was then used to name the ostrich in Biblical Hebrew.
Translations like the KJB, ESV, and the NASB have substantially altered the literal meaning of this verse. One possible reason for this might be that in the East the stork is a symbol of parental love, and the ostrich was known to treat it's young harshly in an attempt to adequately prepare them for the hard realities of their environment (Lam 4:3).
Samuel Bochart (1599 – 1667), the French Protestant biblical scholar wrote, that there is, perhaps, scarce any passage of Scripture which is less understood.