Static equilibrium refers to a state where an object is at rest and remains in that position because the forces acting on it are balanced. This means that the total force and total torque acting on the object are both zero. For example, a book resting on a table is in static equilibrium because the gravitational force pulling it down is balanced by the normal force exerted by the table. In static equilibrium, not only must the forces be balanced, but the object must also not be rotating. This condition is essential in various fields, such as engineering and physics, where understanding how structures like bridges or buildings maintain stability is crucial.