Sweden is Europe's 5th largest country, or about the size of California. For population data, as well as general up-to-date information about Sweden and its history, please visit Wikipedia.
The map to the right shows the province boundaries in Sweden. Provinces date back to the Middle Ages, when they each had their own rulers and laws, and were eventually united into the country of Sweden. In the 17th century they were in some ways superseded by counties, that have been used for administrative purposes since then (e.g. in organizing health care today).
Provinces still exist today, though for cultural purposes. One official use is in royal titles; the Swedish equivalent of e.g. "the Duke of Sussex" refers to a province, not a county. But above all, it's very common to relate one's cultural identity to a province rather than a county. Cultural heritage and tourist information also tends to refer to provinces.
Provinces and counties often share borders, but genealogists typically prefer to use provinces, as counties have been less stable over time (splitting or merging according to political whims—the latest batch of changes was in the 1990s).
Nils Peter Nord and his wife Johanna Svensdotter both came from the same parish in Småland in Southern Sweden.
Teckla Wallin's parents had married in Sweden, a couple of years before they emigrated. They came from different parishes in Västergötland, about 15 miles apart.