First off, the nigga ^^^above me-shut up.
To the OP, lemme take you on a journey....
Sing Mary had a Little Lamb. Its okay, we all real niggas here, no one gonna laugh. That tune you sung- thats a melody. Think of melody as the fingers on your hand. Okay.
Chords are groups of notes played altogether (at the same damn time)
Okay, so, lets say you 'bout to knock a nigga out for eye-fuccin' your main chick while y'all in line at El Pollo Loco. You ain't gonna hit him with all four of your fingers and thumb one at a time, right? You gunna square up, and hit him with that Number 4 combo 2-piece with the dirty rice. If a melody is each of the fingers on your hand, then a chord is like a a balled up fist, feel me?
Melody-individual notes played in succession. Remember when you learned how to count on your fingers, like "Wuuuunnn, Toooo, Treee, Foooooh"? Thats MELODY(A group of individual notes played one after the other)
You get that nigga on the ground, for the stomp-out, to stomp a nigga out we gotta use our feet. Now if our hands have fingers, our feet has toes. Think of all 10 of your fingers as a scale. All ten of your toes are another scale. When you flip someone the bird for cutting you off in traffic on your way to family court-you are playing a note from a scale.
When you throwin' up your set on line in the workhouse chowhall to let them ***** niggas from north side know what time it is-you playing notes from a scale.
Chords-When you raised your hand in class to ask your fine ass young teacher if you could skip recess and smell her *BLEEEP* instead, you raised your whole hand up, right? Not just one finger at a time, but the whole damn hand, right? You just played a CHORD. A chord=A group of notes. We also call this HARMONY(a group of notes played simultaneously)
Now, you throwin' them bows from the shoulder, with total disregard for that nigga life, and future welfare of his kids watchin' him get pieced up like Tina in that limosine, you writin' your masterpiece chord progression.
If your fists are chords made up of notes which are your fingers, then think of a chord progression as a combination of punches. follow me?
Its gets more complicated than that, then it gets simpler once you start to internalize it (Happens faster when you can HEAR it as you're learning it), but this is just a start.