The scammers will try to talk to you and pretend to be working for a big tech company (e.g Microsoft). Usually they claim that they are some sort of technical support and certified in something.
They will tell you that your device has a virus or something similar and will ask you to give them remote access to analyse the problem and fix it.
After showing you some “serious problems”, they will try to talk you into buying expensive and overpriced software which will “fix” your device. A lot of the software does not even do anything.