Which device? There are many makes and models

/e/OS Devices
1

See various makes and models stating the phone is locked. What does this mean? What does unlocked mean? If one is going to reformat the phones OS and install eOS what does it matter if the phone is locked or unlocked?

Prior to purchasing a phone how do I know if my carrier AT&T the phone will work on their system?

Thanks

Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone