Why do they give red envelopes with money instead of normal presents??

According to the Chinese culture, Chinese Character Year (岁suì) has the same pronunciation with the monster's name (祟Suì), the people called the coins Ya Sui Qian, meaning “lucky money warding off the evil spirit”. As time passed, paper notes replaced the coins and the envelope replaced the thread. In addition, red is the most popular and auspicious color in China, so people use this way to share blessings and happiness to each other.