Can anyone help me understand todays MACD histogram reading for crude oil?

General
1


1) when & why do the bars on top / bottom of the zero line ?

2) histogram always has a positive or negative value ..... what do they indicate ?

3) is this indicator sufficient alone or should be clubbed with any other tool as well ?

thank you

2

Please refer the below link for better understanding of MACD histogram with example.

http://stockcharts.com/school/doku.php?id=chart_school:technical_indicators:macd-histogram