smart watches

how do they operate?can it be used to call or receive calls? does it use a sim card? is it charged? can it send sms or what makes it smart…nb: i have googled but am getting no info

S.V keti paaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaale na hizo maswali za NV

https://www.youtube.com/watch?v=WK-kD5zesC8

…kama hauna jibu…go drink ur cheap liqour

Kama hujui ,achana nayo

Yes they can be used to make and receive calls.
It has no sim card. just connects to your phone mainly via Bluetooth and uses your phone to make the call.
yes its charged
it can send an SMS
some watches have a camera you can use to take photos directly instead of using your phone.