A large group of similar specialized cells is called a tissue.

Here's a breakdown:

* Cells: The basic building blocks of life.

* Specialized cells: Cells that have a specific structure and function. For example, muscle cells are specialized for contraction, while nerve cells are specialized for transmitting signals.

* Tissue: A group of similar specialized cells that work together to perform a specific function. Examples include muscle tissue, nervous tissue, epithelial tissue, and connective tissue.

So, tissues are essentially collections of cells that are like a team working together to do a particular job within your body!