Do all cells have a cell wall?

No, all cells do not have a cell wall. Cell walls are only found in plant cells and in some fungi, algae, and bacteria. They are absent in animal cells. There is a reason why all cells do not have a cell wall. Cell walls are very rigid.  They act as an exoskeleton for each cell, providing the cell with crucial structural support and rigidity, which enables plants to stand upright even without bones. However, these same properties also make it more difficult for the cell to move. Animals do not require such rigidity. Instead, the cell membrane that surrounds animal cells provides them with optimum support without compromising on flexibility and movement.