In the United States, it means "you may pass."
divided highway
no passing
it means you can not pass people
No passing.
It separates two lanes traveling in the same direction
It means that your lane cannot pass.
A double solid yellow line in the center of the highway is there to separate the two directions of traffic. In most cases, you should not cross that line. On a two-lane road where passing is allowed, one line (or both) will usually become a dashed yellow line. Some locales do not allow turns off the highway across a double yellow line.
two different lanes
you cannot cross over.
No passing when driving in that direction while it is solid.
No passing by traffic travelling in your same direction.
No passing, when it is on the other side you can pass.