vine: the grapevine, the cultivated plant whose grapes give Israel its wine
Gephen is the grapevine, one of the staple plants of the land. Alongside grain, olives, and the fig, it stands for a settled, well-watered, well-tended life. Its grapes become wine, which the Bible treats as a gift that gladdens the heart, so a flourishing vine signals blessing and a withered or stripped vine signals disaster.
Because the vine mattered so much, it became a natural picture for other things. A man sitting under his own vine pictures peace and security. The whole nation of Israel is pictured as a vine that God dug up out of Egypt, planted, and tended, only to watch it run wild. These are not separate words: they are the one plant seen through different lenses, which is why the same noun carries a literal harvest in one verse and a portrait of the people in the next.
The Bible also knows a darker vine. A wild plant gathered by mistake and the bitter vine of Sodom both borrow the word for something that looks like a grapevine but yields poison instead of wine, the opposite of everything the true vine promises.