The structure composed of two or more tissue types that work together to perform specific functions for the body is called an organ.

Here's a breakdown:

* Tissues: Groups of similar cells that perform a specific function (e.g., muscle tissue, nervous tissue).

* Organs: Made up of different tissues that work together to carry out a more complex function (e.g., the stomach, the heart, the lungs).

Let me know if you'd like more examples or information about organs!