sms and phonecalls

In order to make normal cellular telephone calls and to send and receive SMS/MMS messages, you need a device that can connect to a cellular telephone service provider’s voice network. No iPad can do that nor has any iPad ever been able to do that.

An iPad is a data-only device - it connects to the internet via wifi or cellular if you have a cellular model. As such it is limited to internet only messaging (iMessage between Apple devices, Skype, Google hangouts, etc) and VOIP calling (FaceTime, Skype, etc). An iPad is not capable of using any cellular voice network-specific features or services.

The advantages of a wifi+cellular iPad over a wifi only iPad are that it can connect to the internet where and when wifi is unavailable, and it includes a full aGPS receiver.

If you have an iPhone you can use iOS‘s Continuity feature to pair the iPad with it to share the iPhone’s SMS service - Use Continuity to connect your Mac, iPhone, iPad, iPod touch, and Apple Watch - Apple Support

rudi174 wrote:

This will probably sound stupid to you guys,

No, it doesn't. The only stupid questions are those that aren't asked. If you don't know something, asking is the best way to find out.

rudi174 wrote:

Now that i am using the ipad pro, it is only possible to persons who have iphone's??
My wife has a Galaxy S8, and i can't send a simple sms text message to her phone. Is this correct please? Is this NOT possible with this Ipad pro? or even call her om the samsung phone? I know that an ipad isn't a phone, but the sim card is only there for data transfer or only-iphone messages?

You are correct. iPad is not a phone. It's not limited to Pro models. All iPad devices can not send SMS text message on their own. You need to pair them with an iPhone. You're correct again regarding the SIM card in the device. It is only used to transfer data both direction (in and out). You can, however, install messaging app on both Samsung and iPad device and (voice) call your wife using that app over (cellular or Wi-Fi) data connection or send her text (not SMS) messages with that same app.