Candlesticks versus Bar Charts

Candlesticks versus Bar Charts http://www.financial-spread-betting.com/course/charts.html What's the difference between candlesticks and bar charts? And why are Highs and Lows so important? There is no extra information on the candlestick than there is on the bar chart but there's a more immediate visual representation. Many like it but some don't like the fact that candlesticks emphasise the open and close as opposed to the high and low of the period.