According to the author of the book of Joshua, God told Joshua to give Caleb a special piece of land because Caleb trusted and followed God. This land was in a place called Hebron, and it was a reward for Caleb's faithfulness.
Joshua 15:13: And unto Caleb the son of Jephunneh he gave a part among the children of Judah, according to the commandment of the LORD to Joshua, [even] the city of Arba the father of Anak, which [city is] Hebron. [the city...: or, Kirjatharba]
There could be a contradiction regarding the allocation of land to Caleb. In some parts of the Bible, this land allocation could appear inconsistent with different accounts of which territories were assigned to various tribes or individuals. This might cause some confusion about the exact boundaries or details of the land Caleb received.