What are the different types of road bike shifters available in the market?

The different types of road bike shifters available in the market include integrated shifters, bar-end shifters, and downtube shifters. Integrated shifters are commonly found on modern road bikes and are located on the brake levers. Bar-end shifters are mounted at the end of the handlebars and are popular among touring cyclists. Downtube shifters are located on the downtube of the frame and are a more traditional style of shifter.