When benzyl alcohol (C\(_6\)H\(_5\)CH\(_2\)OH) reacts with thionyl chloride (SOCl\(_2\)), the hydroxyl group (OH) is replaced by a chlorine atom, resulting in the formation of benzyl chloride (C\(_6\)H\(_5\)CH\(_2\)Cl). This is a typical reaction for alcohols with SOCl\(_2\), where the alcohol undergoes nucleophilic substitution.
Thus, the major product is benzyl chloride (C\(_6\)H\(_5\)CH\(_2\)Cl).