Although it is clear that implicit and explicit attitudes are not same, how do they differ is not. I believe establishing the relation between them would surely help deducting it's meaning in context of psychology. It seems that research by Nosek (2007) would be relevant.
Nosek, B. A. (2007). Implicit–explicit relations. Current Directions in Psychological Science, 16(2), 65-69.
Although implicit and explicit attitudes are not the "same" they frequently overlap (e.g. people that are explicitly racist are usually implicitly racist). Both are a positive or negative feeling towards an object. The primary difference between the two is found in conscious awareness of a particular attitude and how the attitude is expressed. Implicit attitudes are unconscious while explicit attitudes are conscious. Explicit attitudes are tempered by things like social desirability. Work with implicit attitudes tests like the IAT have shown implicit biases against things like race, age and sex. Most people do not explicitly subscribe to these biases but still unconsciously harbor latent preferences.
Check out Project Implicit to take a variety of IAT's and learn more: https://implicit.harvard.edu/implicit/
An attitude can actually exist at two different levels. Explicit attitudes are attitudes that are at the conscious level, are deliberately formed and are easy to self-report. On the other hand, implicit attitudes are attitudes that are at the unconscious level, are involuntarily formed and are typically unknown to us.
Explicit attitudes are consciously accessible attitudes that are controllable and easy to report. Implicit attitudes are uncontrollable and perhaps not consciously accessible to us.
