My understanding of how to distinguish second- and third-generation social security cards:

1. Appearance distinction: The second generation has the words "Social Security Card" on the front, and the card number and personal identity information on the back. and card issuers. The third generation has the words "Social Security Card" and the "PBOC" logo on the front, and personal identification information on the back.

2. Chip distinction: The second-generation chip mainly stores electronic medical insurance voucher information, while the third-generation chip supports the storage of basic personal information and various other service information.

3. Differentiation of usage functions: The second generation is mainly used in medical security and retirement insurance, while the third generation provides more scenario payment functions.