Verticulture takes it name from the fact that growing structures are designed vertically to maximize yield per square foot.
Most commonly-seen systems are comprised of large diameter (4") PVC pipe into which multiple plant sites have been incorporated, either by cutting or melting angled openings into which net pots or other grow media can be inserted.
The "grow towers" can have plant sites installed on all sides to maximize plant density. Often, such systems include multiple towers fed from the same pump and reservoir.
Nutrient solution is pumped from a gravity-fed reservoir to the top of the tower, where it trickles down over roots and grow media. Oxygenation is increased by the action of the solution cascading down the inside of the tower. Tower height is limited by the head pressure the pump is able to achieve.