People keep saying use modes to get a different sound. How can you get a different sound from modes when they use the same chords from whichever you built the modes off, doesn't really matter if it's major or minor, that part is confusing?
You don't "use" modes by selecting a scale and randomly playing notes and chords from it without having any sense, skill and control over what you are doing with your notes and chords. A modal scale does not guarantee that any random note chaos will create a modal feeling as long as the notes and chords are selected from the right scale. You need to know what picture you are drawing. Where is the center and what's in it.
A scale doesn't create a mode, it's the musician who creates a mode, often using a scale as a tool. A musician can use a scale and FAIL to create the intended mode in the listener's ear. It can happen if the musician emphasizes the wrong notes or doesn't emphasize the right notes for that mode. The same set of notes, say, the white keys of the piano, can be used to create many different harmonic feelings, and the seven diatonic modes are examples of such harmonic feelings. But there are others, for example, if you cannot feel a harmonic center pitch, then it's not any mode at all.
First you need to have the skill of creating the harmonic feeling of a mode. Only after you can do that, then you can think about when and why you might want to use that mode's feeling. You must be able to bake a cake, and then you can use a cake. If you do not have the skill, you can buy a ready-made cake and use it.
Similarly, you can select a ready-made musical piece that produces the mode you want, and then you can talk about using the feeling somewhere for some purpose. I suppose there are audio and MIDI libraries which have ready-made musical material for various modes. Producers can use those, if they cannot build their own material from lower level ingredients.
How can you get a different sound from modes when they use the same chords from whichever you built the modes off, doesn't really matter if it's major or minor, that part is confusing?
Major and minor keys both use major and minor chords, yet they sound different. The difference lies in the relationship of each chord to the "home" pitch, and, perhaps more significantly, in the relationship of each degree of the scale to the home pitch. Most notably, "modal" music is usually identified (in modern music) by having a raised fourth degree or, most especially, a lowered seventh degree.
(In fact, an increasing fashion for chromatic alteration -- raising the leading tone and lowering the fourth and sixth degrees of Mixolydian and Dorian modes, respectively -- was the primary cause of the modern major and minor scales' developing from modes between the late medieval and early baroque periods of music history. So nowadays chromatic alteration is generally incompatible with the "modal" label, since it typically means that the music is in fact tonal.)
But in popular music, the boundary between modal and tonal music is less clear, in part because of the blue note. You can use a C7 chord as a functional tonic in a song in C major without having to say that the song is in in the Mixolydian mode. The difference between the Dorian mode and the natural minor, a.k.a. the Aeolian mode, is subtle to nonexistent, owing to the flexibility of the sixth and seventh degrees of the minor scale.
In practical reality, where music uses chromatic alteration, the primary feature that makes a song modal is likely to be the melody, with chords that don't necessarily come from that mode's diatonic scale. For example, "Light My Fire" by the Doors contains (looking only at the first verse without the introduction) the chords of A minor, F♯ minor, G, A, D, B, and E. The pitch class set implied by these chords is A, B, C, C♯, D, D♯, E, F♯, G, and G♯. None of the diatonic modes contains all of these pitches. None could, since there are 10 of them. But the melody uses only the pitches A, B, C, D, E, F♯, and G, quite solidly A Dorian.