In my country, when we want to get information about a phone number there are two options available. One is checking national yellow pages and the other is calling a telecom line that provides some information about national phone numbers. If the phone number you´re looking for is registered as non confidential, then you´re lucky, the operator will give you details about that particular phone number such as name of the owner and address. On the other hand, if the phone number is registered as confidential the operator won´t provide any information about it. This is how things work here.
In US, there are different companies that provide phone number information services. If, for any reason, you need information about a phone number you can check it online, using Caller Wiki Report, a service that doesn´t exist here.
Trough Callerwiki website you can learn if a number belongs to a telemarketing or other company. Users can read what others have written about that number too. There´s also a reverse phone lookup available to all users. Maybe in a few years a useful service like this will be developed here but for now we only have the two options of having information about a phone number mentioned above