Open - This is the price of the first trade for the period. When analyzing daily data, the Open is especially important as it is the consensus price after all interested parties were able to "sleep on it".

High - This is the highest price that the security traded during the period. It is the point at which there were more sellers than buyers.

Low - This is the lowest price that the security traded during the period. It is the point at which there were more buyers than sellers.

Close - This is the last price that the security traded during the period. Due to its availability, the Close is the most often used price for analysis. The relationship between the Open (the first price) and the Close (the last price) are considered significant by most technicians. This relationship is emphasized in candlestick charts.

Volume- This is the number of shares (or contracts) that were traded during the period. The relationship between prices and volume is important.

Open Interest - This is the total number of outstanding contracts of a future or option. Open interest is often used as an indicator.

Bid - This is the price a market maker is willing to pay for a security.

Ask- This is the price a market maker is willing to accept.