What’s the difference? Biblically, a lot. In this sense: happiness is dependent on circumstances, whereas joy is centered on that which is eternal, unchanging, immutable. The term joy in Hebrew is: sameach. It is a word picture, since The Word of GOD is living and active, Hebrews 4:12, each word, even every letter are scenes and frames of the movie. Come and see.Simchah. The Hebrew Word for joy, really ,=means, at a deeper level: The Name at the gate of The Spirit. Amazing. Let’s look at joy more closely. The Name, connotes the nature, identity, character, and essence of someone, or something. The Next letter in Hebrew connotes the gate, and the last letter connotes the spirit. (There are other shades of meaning for these, but this suffices for our current discussion). So, the word picture for joy, from The Original Language of The Bible, Hebrew, is: The Essence at The Place of judgment/authority/decision making, of The Spirit. Thus, this joy is truly a fruit of The Spirit, Galatians 5:22. Thus to know, experience this joy, is to know intimately the essence and nature of the place where decisions are made, judgment is passed, and authority is known and recognized according to the Spirit of GOD. You will know the true nature of something when you have to make a decision, pass a judgment, according to The Spirit of GOD. This brings pure joy, for you know you have made and known the right choice, according to the spirit, as you have known the true essence of the situation. Most people are robbed of true joy for they seek happiness, not joy, a quick fix, instead of lasting joy, a fleeting appearance, as opposed to an eternal security. Knowing true joy is to know the essence of things at the place where it matters most as you align with The Spirit and Truth. That’s joy.