本人 (běnrén) means “this person in question” or “in person” and is very formal. You will see it on official forms, legal documents, or in public notices. For example, a sign might say “请本人前来办理 (Qǐng běnrén qiánlái bànlǐ),” meaning “Please come in person to handle this.” Using
本人 in casual conversation would sound very strange and overly formal.