Day trading charts can be based upon several different criteria, with the most popular being time, ticks (number of trades), volume (number of contracts), and price range. All four types of charts use the same market information (price, volume, etc.), but they display the information slightly differently.
Charts based upon ticks make a new price bar (or candlestick, line, etc.) every time a specific number of trades are completed. Popular numbers of ticks are 33 ticks, 133 ticks, and 233 ticks, which are all short term timeframes. As tick based charts only make new bars when there have been enough trades, they adjust to the market, making bars less often when the market is moving slowly. Some day traders believe that this gives tick charts an advantage over time charts, but this really depends upon the trading system being used.