Apart from the three terms, there are other terms that are concerned with the sustainable development of tourism. Let start with alternative tourism itself:
Alternative tourism: the opposite of mass tourism. Although mass tourism promoted economic development in terms of jobs, it also resulted in negative effects such as economic leakages, environmental, and social impacts. Alternative tourism aims at addressing the shortcomings of mass tourism.
Overtourism: concerned with the excessive number of visitors leading to negative effects on the host and the environment
Voluntourism: The central principle is that the visitors would give back (do charity events) for the communities in the destination.
Community-based tourism: CBT occurs where visitors are hosted by locals. Communities are the key stakeholders in this model where they exercise greater control and get more benefits that they would receive.
Conscious travel/tourism: it has its basis on the corporate social responsibility that favors values-based triple bottom line approach.
Ethical travel: It basically advocates for people to be mindful of travel choices based on moral values and judgments
Slow tourism: advocates for living as opposed to staying in a destination. That is, visitors need to connect to cultures.
Geo-Tourism: while ecotourism focuses on the flora and fauna, geo-tourism adds the dimensions of the abiotic environment.
Pro-poor tourism: Although controversial, pro-poor tourism seeks to put poverty of host communities at the center of the sustainability debate.
Farm tourism: Also called agrotourism and involves green tourism of farms.