I tried youtube, to understand the sound but am unable to distinguish among the two. Any help would be appreciated.
Since you asked in English, I'll assume you are familiar with English pronunciation. The English words for "stimmlos/stimmhaft" are "unvoiced/voiced". The English voiced "s" is generally written as "z", if you pronounce it you should feel a vibration in your throat.
Pairs of English words with unvoiced/voiced "s" are:
- sue - zoo
- see - zee
- sink - zinc
German has the same unvoiced/voiced "s" ("s" can be either voiced or unvoiced, "ss" or "ß" is always unvoiced). The usage is different (and dialect dependent) , but that has been covered elsewhere on this site: Wann wird das stimmhafte "s" gesprochen?