What happens when you are forced to leave the only home you've ever known, and are expected to either make a new life for yourself, or die? This is the question that Banished asks you, and it's to you to decide the fate of not only yourself, but of the group of people that are looking to you for guidance and help.
In the game, you play as a leader of an exiled group of people who have nothing but the clothes on their backs and a simple cart of supplies. Using just this, you'll need to rebuild everything, and do so in a land you do not know. But fear not, for you are not alone in building things, in fact, the whole group of people you're leading are in fact your greatest resource.
For through your combined efforts, you can rebuild, and you must guide them to make that happen. Like real people, your group can work, grow, learn, get hurt, get sick, get well, make families, and more. Use them to get the most essential things done, so slowly work your way up so that you can have a thriving community where everyone is happy, and healthy, and fed.
There isn't a simple skill tree here, nor is there a need to have one. You can build whatever you want whenever you want, that's the beauty of Banished. If you feel there is a need for something, get the people together and make it. Have the people learn jobs to make the town grow even more advanced, and become better. How you build your new home will define how the people survive, if they do at all.