In the second season of Veronica Mars the topic of incorporation of Neptune comes up. I am not from the US so this concept is alien to me. Can someone explain what this means in this context?
The fictional Neptune was an unincorporated town.
In law, an unincorporated area is a region of land that is not governed by its own local municipal corporation, but rather is administered as part of larger administrative divisions, such as a township, parish, borough, county, city, canton, state, province or country.
Its 'mayor' was the County Supervisor (Woody Goodman) and it was policed by the County Sheriff (Don Lamb). Woodman basically wanted to make it an official town:
The second season explored these political elements with plotlines involving an election for the offices of Sheriff and County Supervisor, with Keith Mars (supported by Goodman) trying to get his old job as sheriff back by running against Don Lamb. While Keith lost his bid to reclaim his old job, Goodman won his election. Afterwards, he showed his ambitious side by launching a campaign to incorporate Neptune, which would lead to the town having an official mayor and its own police department, with the municipal boundaries only including the "09er" sections of town. Those outside this incorporation area came under risk of lower property values and even further reduction in government response and effectiveness.