A tissue is a group of similar cells that work together to perform a specific function. Here's a breakdown:

* Similar cells: The cells within a tissue share a common origin and structure, which enables them to carry out their specific task.

* Specialized activity: Tissues are designed to perform particular functions in the body, such as muscle tissue contracting, nervous tissue transmitting signals, or epithelial tissue providing a protective barrier.

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