A deferred decision in a VA Disability Claim just means that the decision is delayed. Usually it is delayed for further development like ordering an exam for the condition that is deferred.
For instance, when you filled for benefits, you may have filed for VA Disability Depression, Back Pain, Headaches, and bilateral(both left and right) Hip Pain. The VA may have enough medical evidence to decide your claims for VA Disability Depression, Back Pain and bilateral hip pain, but they still need more evidence to decide if your headaches are service connected.
A deferred decision is a neutral decision. It is neither good nor bad and is not a predictor of the outcome of your claim. Once the VA has further developed the deferred claim they will send a separate rating decision to the veteran.