If you have a dual SIM variant, you can have 2 SIMs in your phone, for example, one for your work and one for your personal use.
Note: On dual SIM capable devices, both SIM1 and SIM2 slots support 4G networks. However, if your SIM1 and SIM2 are both LTE SIM cards, the primary SIM supports 4G/3G/2G networks, while the secondary SIM can only support 2G. For more information on your SIM cards, contact your service provider.
When, for example, making a call, you can choose which SIM to use by tapping the corresponding SIM 1 or SIM 2 button after you dial the number.
Your phone shows the network status for both SIMs separately. Both SIM cards are available at the same time when the device is not being used, but while one SIM card is active, when, for example, making a call, the other may be unavailable.
Don't want work to interfere with your free time? Or do you have a cheaper data connection on one SIM? You can decide which SIM you want to use.
Tap the SIM you want to rename, and type in the name you want.