Picture of a beautiful real-life green wall of plants

Quick answer：

A green wall, also known as a living wall or vertical garden, is a vertical garden that is attached to a wall. It consists of plants grown in a series of stacked planters or pockets that are fastened to a building. These walls are designed to provide aesthetic appeal, improve air quality, and offer insulation benefits. They are commonly used in urban settings to create green spaces where they might otherwise be scarce.