pls explain the resonance effect (+R effect) and (-R effect) with the help of aniline and phenol.

In phenol, the -OH group shows +M or +R effect due to delocalization of lone pair on oxygen atom towards the ring. Thus the electron density on benzene ring is increased particularly on ortho and para positions.

Hence phenol is more reactive towards electrophilic substitution reactions. The substitution is favored more at ortho and para positions. 

The -NH₂ group in aniline also exhibits +R effect. It releases electrons towards benzene ring through delocalization. As a result, the electron density on benzene ring increases particularly at ortho and para positions. Thus aniline activates the ring towards electrophilic substitution.

It is also worth mentioning that the electron density on nitrogen in aniline decreases due to delocalization which is the reason for its less basic strength when compared to ammonia and alkyl amines.