In its simplest form Skatteverket is the agency in Sweden that collects everyone’s taxes. It also manages population registration. If you are moving to Sweden and plan on spending one year, or more, you should register as a private individual and apply for an ID number or “Personnummer”.
Once you have been registered and received your personnummer you can apply for an ID card. As well as passport and driving licence, the Swedish ID card is thought of as the number one valid form of identity.
Depending on your circumstances there are different things you need to bring and ask when you are registering with Skatteverket.