Rabbi Adin Steinsaltz writes:
“The day celebrated as Shavuot, the day of the giving of the Torah by God, is sometimes also called the day of the receiving of the Ten Commandments by Israel.
And it would seem to be a natural pairing of concepts—the giving and the receiving being the two sides of the same action and apparently interchangeable as descriptions of the event.
Nevertheless, they are not identical.
Each has its own particular meaning, in terms of ideas as well as in historic actuality.
As the Kabbalah puts it, the giving of the Torah is a movement from the above to that which is below, while the receiving is a movement from below reaching upward.
And in the dimension of time, the giving of the Torah is essentially a single act, while the receiving of the Torah is a diversified and continuing process in history.
–Rabbi Adin Steinsaltz in “Talmud” from The Strife of the Spirit