Historical anomalies and aspirant states
A small number of micronations are founded with genuine aspirations to be sovereign states. Many are based on historical anomalies or eccentric interpretations of law, and tend to be easily confused with established states. These types of micronations are usually located in small (usually disputed) territorial enclaves, generate limited economic activity founded on tourism, philatelic and numismatic sales, and are at best tolerated or at worst ignored by other nations.
Social, economic, or political simulations
Micronations of this type tend to be fairly serious in outlook, involve sometimes significant numbers of relatively mature participants, and often engage in highly sophisticated, structured activities that emulate the operations of real-world nations.
Exercises in personal entertainment or self-aggrandisement
With literally thousands in existence, micronations of this type are by far the most common. They are ephemeral, rarely surviving more than a few months; although there are notable exceptions. They generally involve a handful of people, and are concerned primarily with arrogating to their founders the outward symbols of statehood. The use of grand-sounding titles, awards, honours, and heraldic symbols derived from European feudal traditions.
New-country projects are attempts to found completely new nation-states. They typically involve plans to construct artificial islands (few of which are ever realised). A large percentage have embraced or purported to embrace libertarian or democratic principles.
Seasteading is a lifestyle of making the oceans, or at least water-borne craft, one’s home. Most seasteads historically have been sailing craft. Nowadays, all sorts of floating crafts are used. Some theoretical seasteads are floating platforms which could be used to create sovereign micronations, or otherwise serve the ends of ocean colonization.
See other: Posts on Micronations