Dose ID Conflict happens? (UUID or auto-increment)

[Ashkar Dev <ashkardev@xxxxxxxxx>]

Hi,

for web application is it needed to use UUID or auto-increment?

1- if two user inserts row at the same time, does it work?

2- dose the database give the same id for both users or execute one of them first? ( I mean ID conflict not happens?)

(using PostgreSQL database with PHP)

Thanks.