Here's why:

* Cells: The basic building blocks of life.

* Tissue: A group of similar cells that work together to perform a specific function.

For example:

* Muscle tissue is made up of muscle cells that contract to allow movement.

* Nervous tissue is made up of nerve cells (neurons) that transmit electrical signals to communicate information throughout the body.

* Epithelial tissue forms linings and coverings, like the skin.

Let me know if you have any more questions about cells and tissues!