Why does the flame flare up when air being blown while kindling firewood?

When air is blown onto a fire, it increases the supply of oxygen, which is essential for combustion. The additional oxygen enhances the chemical reaction between the fuel (wood) and the heat, causing the flames to become more vigorous and flare up. This is why blowing on a fire can help it burn more brightly and intensely. However, care should be taken, as too much air can also extinguish a small flame.