This is the 174th most frequent Russian word.
его
"His" or "him" (possessive or object pronoun).
The word 'его' is used as a pronoun meaning 'him', functioning as a direct object of the verb 'видел' (saw).
Я видел его в магазине.
I saw him in the store.
The word 'его' is used as a possessive pronoun meaning 'his', modifying the word 'столе' (table).
Книга лежала на его столе.
The book was lying on his table.
In this sentence, 'его' is used as a possessive adjective meaning 'his', describing the word 'мнение' (opinion).