Electrophilic substitution reactions happen in different ways when it comes to aromatic compounds. Here are the main reasons why:

1. Substituent Effects:

   • Some groups can give extra electrons to the ring. These are called electron-donating groups. Examples are -OH and -NH₂. They make the ring more reactive.
   • Other groups pull electrons away from the ring. These are known as electron-withdrawing groups. Examples include -NO₂ and -CN. They make the ring less reactive and change where substitutions happen.

2. Steric Hindrance:

   • Big groups on the ring can make it harder for other molecules (called electrophiles) to get close. This can change where the substitution takes place.

3. Ring Stability:

   • Different types of aromatic compounds, like naphthalene and benzene, respond differently in these reactions. This is because some compounds are more stable due to their special structure, known as resonance.

It's all about how these different factors work together!