The structure found in both plant and animal cells is the cell membrane.

Here's why:

* Cell Membrane: This thin, flexible layer surrounds the entire cell and controls what enters and exits the cell. It's essential for maintaining the cell's internal environment.

While both plant and animal cells have a cell membrane, they differ in other structures:

* Plant Cells: Have cell walls, chloroplasts, and large vacuoles.

* Animal Cells: Do not have cell walls, chloroplasts, or large vacuoles. They may have lysosomes and centrioles.