As per the first poll here is the low down on townsfolk and NPCs.

Residents:

Residents are the ordinary day to day people encountered in and around town in game. They will live out their day to day lives in loops decided by the games year, season and day, appearing at certain places, working and offering services or just talking to the player. Alongside this, residents will be involved in certain events throughout the year where their behaviour will be unique and offer something to the player. like a relationship boost if talked to and given gifts on a birthday, The player reaching certain milestones or town events.

Guests:

Exclusive to the Hotel career, guests will arive from out of town to stay at your hotel for a few days. they need to be kept happy by being served food morning and evening, cleaning their rooms and interacting with them. They will wander the town during the day and at the end of their stay they will leave but if interacted with enough they will be added to the NPC pool.

Out of towners:

out of towners are an npc that is not encountered anywhere in the main town of the game. Nor do they have specific events or dialogue. They are random generated upon entry to the city and are usually only encountered once. Though like guests if intereacted with enough they are added to the NPC pool and my crop up later. It will be possible to marry an out of towner with enough effort however and they will move into the town with the player.

spouse:

A spouse is any romancable character that has been married by the player. in doing so they will be disabled in the town database and the spouse NPC will take on their characteristics. They will then attend their own jobs and go about their own buisness but have a number of requestable interations with the player. NPCs can be romanced and married regardless of gender in game.

Pool:

Pool npcs are npcs that have been flagged for repeated use in game. such as regular guests and customers. Out of towners who have been befriended or romanced in the city will also begin to appear as paying customers to the players various buisnesses rather than be deleted when the city generates its next set of npc's