Aromatic directing groups

Question 1

What are electron donating groups?

Answer 1

-OH and -NH2 groups donate electrons into benzene ring, increasing e- density of delocalised pi ring. Benzene is more reactive So reactions occur more readily.
Substitution occurs at positions 2&4 (ortho- & para-)

Question 2

What are electron withdrawing groups?

Answer 2

-NO2 substituent groups withdraws electron from benzene ring, lowering e- density of delocalised pi ring. Benzene less reactive. Reactions occur less readily.
Substitution occurs at position 3 (meta-)