Introduction
Dolibarr setup is done on 2 levels. First level is global (setup applies for every users) and second level is by user (setup applies for a particular user only).
Global setup (all users)
All global setup is saved into table llx_const. Each parameter is defined by a key (name of parameter) and a value in this tables. All this constants can be edtited from menu "Home - Setup" (every data in this menu and submenus are saved in this table).
Other fields in this table are not mandatory. The field note contains a description of the goal of parameter.
By user setup
All setup particular to a user is saved into table llx_user_param. In this table, it's field fk_user that contains the id of concerned user. You will find also a key (name) and a value. All thoose parameters can be edited from the user card, tab "User setup".