While the majority of road groupsets are mechanical, using cables from the shift levers to change gears, there are a growing number of road bikes that now come fitted with electronic shifting, where a motor shifts the derailleurs between ratios.
The main electronic systems are Shimano Di2, Campagnolo EPS and SRAM eTap AXS, which all offer 12 speeds.
There are benefits and drawbacks of both mechanical and electronic options.
Mechanical components, such as mechs and levers, are generally cheaper and lighter than their electronic counterparts. They are also, for the most part, easier to fix when something goes wrong.
Electronic gears benefit from reliable shifting. There's no cable tension at play here. If you've suffered a hand injury, the ease of changing gear with the press of a button could be appealing. Electronic gearing can be personalised through an app, allowing you, for example, to shift multiple gears seamlessly. However, all this tech doesn't come cheap and complete road bikes fitted with electronic gears will be more expensive.