What is "Unlocking" on a phone and what are the pros and cons?

[usere085q6oijf]

What is unlocking if a phone and what are the pros and cons? I have a Galaxy Note 20 Ultra 5G.

[LongHiker]

@usere085q6oijf Carrier unlocking a phone allows you to take a phone to another carrier for service. 

[userjlovLIyGpH]

Means it can be used on any gsm carrier. If it is unlocked through a carrier then that carrier needs to unlock the branded phone....att/tmobile and so forth. Unlocked from factory means it isn't assigned to a carrier.

[TheGalaxy · Accepted solution]

The term refers to the cellular network connectivity limitation by providers.
A factory unlock phone is able to connect to any cellular network (AT&T, T-MOBILE. VERIZON, etc).

A locked phone is locked to a certain network carrier.

Check
Settings
About phone
Software information
Service provider software version
To find out what is the status of your phone.

[usere085q6oijf]

So using these steps, I have discovered my phone is still locked to AT&T instead of my provider who is Tmobile. Thank you for the info

[TheGalaxy]

Actually
Let's interpret what we see
It's the last there letters that determine the status of your phone.

[usere085q6oijf]

The last three letters is AT&T.

[TheGalaxy]

Then your phone was originally an AT&T phone

[LongHiker]

@usere085q6oijf "So using these steps, I have discovered my phone is still locked to AT&T instead of my provider who is Tmobile."

Not possible. If it is locked on AT&T you wouldn't be able to use a Tmobile SIM. 

What you have discovered is that your phone has AT&T firmware installed instead of the Tmobile firmware. 

[usere085q6oijf]

I agree. I was going to take a trip to the AT&T store and get them to unlock my phone.