Electrophilic aromatic substitution is a chemical reaction where an electrophile replaces a hydrogen atom on an aromatic ring. Aromatic compounds, like benzene, have a stable structure due to resonance, making them less reactive. However, when an electrophile approaches, it can temporarily disrupt this stability, allowing for substitution. During the reaction, the aromatic ring donates electrons to the electrophile, forming a positively charged intermediate called a sigma complex. This intermediate then loses a proton, restoring the aromaticity of the ring and resulting in a substituted aromatic compound. Common electrophiles include halogens, nitrating agents, and sulfonating agents.