Flame types can be categorized based on their appearance and temperature. The most common types include yellow flames, which indicate incomplete combustion and produce soot, and blue flames, which signify complete combustion and are more efficient. Red flames are often cooler and can be seen in certain chemical reactions, while green flames may occur when specific metal salts are burned. Different flame types are used in various applications. For instance, Bunsen burners produce a blue flame for laboratory experiments, while candles typically emit yellow flames. Understanding these flame types helps in selecting the right source for heating or lighting needs.