When I started as an adult there were no "gravel" bikes. Just road and mountain. I started mountain biking first. When I met my future father in law he was a roadie and convinced me to try road. That and a recurring shoulder issue from an old hockey injury made me switch to road full time. These days I'm doing mild gravel and road. As much gravel as my shoulder will allow. I'm going to have surgery on it later this year and see whee I am after that.