What should I pay attention to when buying digital cameras online?

Upstairs is from the perspective of parameters and performance. Let me just say: 1 from the perspective of safety. Do you want to know whether it is licensed, guaranteed or guaranteed? How long will it last? 2. Are there any other invoices, instructions, warranty cards and original packaging? 3. What if there are quality problems? Repair postage? Say the ugly words first. 4. When receiving the goods, be sure to open the box and check that there is no leakage before signing for it; 5. Don't rush to confirm and evaluate, just let the system automatically confirm and evaluate. 6. Don't contact the seller by phone, QQ or SMS.