Dialect or language?
It is not always easy to determine whether some linguistic varieties are dialects of the same language or separate (closely related) languages. A common view is that speakers of different dialects of the same language understand each other, whereas speakers of different languages do not. The distinction is not, however, always this straightforward. For example, Swedish and Norwegian are so similar to each other that their speakers can understand each other without any major difficulties, yet Swedish and Norwegian are regarded as two different languages, as they are the languages of two different states and two different nations.
A language called Meänkieli that resembles Finnish is spoken on the Swedish side of Torne River Valley. Meänkieli is very similar to the Far North Finnish dialect spoken on the Finnish side of the border. From the Finnish-speaker’s perspective, Meänkieli could be regarded as a dialect of Finnish. However, in Sweden Meänkieli has been granted an official minority language status and is regarded as a separate language from Finnish.
Dialectal differences can also be seen as kinds of drifts. For example, the number of Saami languages still spoken today is around ten. Speakers of Saami languages who live close to each other usually understand each other even though they speak different languages. On the other hand, speakers of different Saami languages who live very far away from each other do not necessarily understand each other.
The Finnish language has many dialects but one literary language that is common to everyone. Some Uralic languages have two or more literary languages. Not all Uralic languages can be studied in school, and there are some that do not have a literary language common to its speakers. In some cases, individual persons or the speakers of the same dialect write their own language in their own, slightly unique way.
Consequently, it is sometimes very difficult to draw the line between a dialect and a language. This is also why it is hard to specify the precise number of Uralic languages or the precise number of different languages in the word.
You can take a look at the online Meänkieli dictionary to compare Finnish and Meänkieli and see whether you think they are separate languages or dialects of the same language.
Sources:
Ahola, Elina 2012: Suomen sukukielet [Linguistic relatives of Finnish]. In Suomen kieli. Opiskelijan tietokirja 2 [The Finnish Language. Textbook for Students 2]. Publications of the Department of Finnish and Finno-Ugric Languages of the University of Turku 1.
Korhonen, Mikko 1993: Kielen synty [The Birth of a Language]. WSOY.
Laakso, Johanna 1999: Karhunkieli. Pyyhkäisyjä suomalaisugrilaisten kielten tutkimukseen [Bear Tongue. Sweeps of Research into Finno-Ugric Languages]. Finnish Literature Society.