The Sims is a series of life simulation games, made by maxis and published by EA. The game series started off as a spin off of Maxis SimCity from 1989, a game where you devopled a city. The idea of the Sims was a virtual dollhouse where you controll and take care of the Sims. The Sims 1 was relessed in 1999, followed by the Sims 2 in 2004, then sims 3 in 2009 and the sims 4 in 2014. Although the Sims did not start out as a game with a specfic story, through expansion pack and later games you will discover the stories of different townies (npc) and find out the main mystery on what happened to Bella Goth.
Its important to know the timeline of the mainline Sims games as it important to understanding the lore of the games. Because the Sims started of with no story intended, the timeline actual goes Sims 3, then the Sims 1 and finally the sims 3. The reason the Sims 4 is not in this timeline is its believed to be in an different universe cause by time travel perhaps inbetween the Sims 1 and The Sims 2. It has no real lore present and will not be of any importance to the lore. Its also important that throught this timeline we will be following the Goth family as the main focus is them.
The Goth family in the Sims is one of the townies familes, with the members being Bella Goth the mother, Mortimer Goth the father, Cassandra Goth the daugheter and Alexander Goth the son. The family lives in pleasent view in the sims 2, sunset valley sims 3, and in 1 the starter town. It is belive that all of the Goth money comes from being involed with the founding of pleaseant view. one thing important to know is because of how the timeline is setup in the sims 1 the Goth family is Mortimer and his parents Gunther and Cornelia Goth. In the sims 2 we do not see bella goth cause shes missing.