Turgor pressure is the force within the cell that pushes the plasma membrane against the cell wall.
Mature squirting cucumber fruit
Tree roots penetrating rock
Mimosa pudica
Shaggy ink caps bursting through asphalt due to high turgor pressure
A cell wall is a structural layer that surrounds some cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier. Another vital role of the cell wall is to help the cell withstand osmotic pressure and mechanical stress. While absent in many eukaryotes, including animals, cell walls are prevalent in other organisms such as fungi, algae and plants, and are commonly found in most prokaryotes, with the exception of mollicute bacteria.
Photomicrograph of onion root cells, showing the centrifugal development of new cell walls (phragmoplast)