A follower is your basic 'townsperson'.
Followers are converted from non-believers at a certain rate decided by your Welfare building.
Once converted from non-believers, followers must be housed before they can work for you; a homeless follower can do nothing.
You start off with a certain number of houses already built, and you can build more. You may increase the number of houses you can build by researching the relavant items in your Welfare building.
Once a follower has a house, they can be assigned using the Patria Manager to work in any building you currently have. A follower can also be recruited into your army by using the army management menu in the rts game client.
A worker can be fired from their job, but will be depressed for a certain amount of time (decided by your Hospital building) before they may be reassigned to work elsewhere or recruited into your army.
A recruit that is removed from the army does not go through depression.
Both conversion time to a follower from a non-believer and depression duration can be instantly finished by spending Aeria Points.