Answer:
Both.
Some plants have vascular systems, while others do not. Most plants that we commonly think of, like trees, flowers, and bushes, are vascular. Some simpler plants, like moss and ferns, are nonvascular.
In plants, a vascular system is analogous to the heart, veins and arteries of an animal (which is why it's called a cardiovascular system). It is a system of "tubes" that transports water and nutrients throughout the plant. Mosses don't need vascular systems because they are not very tall, so the water doesn't have to reach very far.