For traditional landline residential service in the US there are 3 types of calls. Local, local toll and long distance. The US is divided into Local Access and Transport Areas (LATA). Each LATA is also divided into local exchanges. Each LATA is operated by a Regional Bell Operating Company (RBOC).

Local calls are calls which stay within a local exchange and there is usually no charge for them. Calls between local exchanges within a LATA, intraLATA, are local toll calls and are billed. These days there is expanded local exchange calling which allows for calling between certain local exchanges within a LATA without a fee, but back in the day this didn't really exist. Long distance calls are those which go between different LATAs.

Local toll calls were the most expensive calls to make because there was no competition for those calls. There were multiple competing long distance services which kept costs lower for those.

Depending upon where your local exchange boundary fell calling a local BBS could be more expensive than calling one that was across the country. My local user group BBS was physically located 20 miles from me but was in my local exchange so no charge to call. A friend who was physically located 2 miles from me ran a BBS and it was an expensive local toll call for me.

This is based upon how the system has worked since the AT&T breakup in the early 80s. Not sure how it worked prior to that. I didn't start using BBS's until shortly after the breakup happened.

In the early days in the US every call was billed. If your call was to another city or even area code then it was a "toll" call and was even more expensive. That sparked the traffic in stolen calling card codes (an account with a long-distance telephone company). Most of these "codes" were only 4 digits so many people wrote programs to brute-force the codes. Then they were traded rapidly to spread the blame and, again, were treated as currency.

Later on some phone companies offered "call-paks" which allowed unlimited calls to numbers in the same area code. But that still didn't cover long-distance. FIDOnet was a clever way to let you call locally and still work nationally.

Operation Sundevil took down a lot of the hubs for trafficking LD codes, but by that time a lot of BBSes were turning into internet ISPs and modeming over long distances wasn't necessary. Things faded off after that.