Here's a breakdown:

* Tissues: Groups of similar cells working together to perform a specific task. Examples include muscle tissue, nervous tissue, connective tissue, and epithelial tissue.

* Organs: Structures made up of different tissues that work together to perform a complex function. Examples include the heart (muscle tissue, nervous tissue, connective tissue), the lungs (epithelial tissue, connective tissue), and the stomach (muscle tissue, epithelial tissue, connective tissue).

Let me know if you'd like more examples or have any other questions about tissue and organ organization!