This is the 5313th most frequent Japanese word.
"Facebook" in Japanese refers to the social media platform Facebook, used for networking and sharing content.
In this sentence, Facebook is a proper noun referring to the social media platform. It is used as the direct object of the verb "チェックします" (check).
私は毎日フェイスブックをチェックします。
I check Facebook every day.
Here, Facebook is again a proper noun and is used as the tool through which an action, sharing photos, is performed. The verb "使って" indicates the means or method.
フェイスブックを使って写真を共有しました。
I shared a photo using Facebook.
In this example, Facebook operates descriptively to specify the posts being referenced, meaning posts made on the Facebook platform. The possessive form "彼の" contextualizes it to a specific individual's account.