If it's something like D/A then this means that it is a chord (D major) with an A note in the bass. So, if you're playing piano then you would play a D major chord in the right hand and an A in the bass.
If it's something like "D/A" then this means that it is a chord (D major) with an A note in the bass. So, if you're playing piano then you would play a D major chord in the right hand and an A in the bass.