Friction - will transfer $\overline{e}$ from one surface to another. A surface which has a greater affinity for $\overline{e}$ compared to another surface will gain $\overline{e}$
Static charge - buildup of charge Electroscope can only tell whether chared or not, can be +ve or -ve
IF electrons are redistributed on an object to produce regions of different charge i.e. an electric dipole, then this is charging by induction - the separation of charge is temporary and will reverse once the induction charge is removed.
IF electrons are physically transferred then the lost/gain of charge is not temporary $\therefore$ charging by induction.
