The carnation is symbolic because as the people were marching with their guns, ready to overthrow the unfair dictatorship, an elderly woman selling carnations started placing carnations in the soldier's guns, and on this day, the dictatorship was overthrown without a single shot being fired.
Now, thousands of people come to celebrate this special day, there are hundreds of parades all around Portugal, there are fireworks, delicious food, and a lot of happiness.