Cell wall

Did you know that cell wall's are only around plant cells? And they are also made of cellulose. You can think of cellulose as a frame of a picture it protects the cell in order for it to survive.
The cell wall also provides the plant to maintain  it's shape.This also allows the plant to grow great heights. Unlike the plants they don't have skeletons like we do so they use the cell wall to keep up right.
When it is a smaller plant it is slightly elastic. If wind pushes them over they go right back up.
If you are thinking that nothing can hurt the plant like the cell wall is a barrier around it your wrong. It still can get hurt.
There are small holes that let ions, waste and nutrients pass through the cell.
These hole's are called Plasmodesmata.