Here is the vane from above, on a day when the wind blows from the north.

The vane from above. The wind blows in from the north. The arrow's point sits on the N.

The wind blows from the north. The point swings to the N.

The arrow points into the wind.

The letter under the point says where the wind is from: north.

A wind from the north is called a north wind.

The point on the N: the wind is from the north. A north wind.

Now the wind blows from the west. The point swings to the W.

The wind is from the west: a west wind.

The point on the W: the wind is from the west. A west wind.

And now the wind blows from the south. The point swings to the S.

The wind is from the south: a south wind.

The point on the S: the wind is from the south. A south wind.