OG Vibes are often confused with being the Original version of a song; which itself is based on the master recording.
An OG Vibe is a remastered version of an original song that uses a beat similar(but not the original) to the original track it was recorded to.
This can be done to bring clarity to an old track, or done simply because the original music has not been released, lost.....ect.
Person 1: Man, I'm tired of all these lame remixes and albums taking Tupac vocals and putting them to modern beats. Glad I found this rare OG Tupac song, sounds so much better.
Person 2: I agree, this unreleased Tupac track is great, but it's not the original.
Person 1: What do you mean?
Person 2: It's an OG Vibe.