I'm looking to create this textured look for my project. I know how to create textured gradient. But I don't know how to achieve this look for the overall artwork in illustrator. Is it a kind of paper texture or vector texture or just the the grain effect in illustrator?
It's possible that this was created with the default Illustrator grain texture.
If you're only looking to match the overall texture and not the slightly-darker accentuating bars, you can go to Effect > Texture > Grain and set the intensity to a low value.