Adoration and Exposition are generally words for the same thing. The host is placed in a monstrance upon the altar. What the priest or deacon does is exposition. What we all do is adoration. Of course, adoration can mean other types of worship.
Benediction means a blessing and many types of blessing are called benediction. Benediction of the Blessed Sacrament is a particular ceremony that includes exposition and the blessing of the congregation with the host in the monstrance. If there’s no blessing, it’s not benediction.