Was Jesus born in a stable? Or could it have been a cave or a house? The easy answer to this is that we do not know for certain because the Bible does not specifically answer this question. However, we can reason through this and consider where it might have been. Tradition tells us it was a stable. That claim is based on the fact that at birth Jesus was laid in a manger.
"And she brought forth her firstborn son, and wrapped him in swaddling clothes, and laid him in a manger.... And this shall be a sign unto you; Ye shall find the babe wrapped in swaddling clothes, lying in a manger." (Luke 2:7, 12)
The Greek word for manger is phatne and The Strong's Dictionary defines it as:
phatne, fat'-nay; from pateomai (to eat); a crib (for fodder):–manger, stall.
A manger was a type of feed trough for animals. Therefore, nativity scenes that depict a baby in a straw laden feeding trough are biblically accurate. Since Jesus was "laid in a manger" (Luke 2:7), it is likely that there were animals nearby, as nativity scenes always depict. However, the Bible does not tell us that.
While traditionally it has been thought that Jesus' birth took place in a stable, some think it might have been in a cave because there are historical records to suggest animals were also kept in caves. Again, the Bible does not tell us about the shelter that held the manger in which Jesus was laid.