What are the different types of bathtub faucet handles available in the market?

The different types of bathtub faucet handles available in the market include single-handle, double-handle, and knob handles. Single-handle faucets have one lever for controlling both hot and cold water, while double-handle faucets have separate handles for hot and cold water. Knob handles are round or square knobs that are turned to adjust the water temperature and flow.