Like many widely-spoken languages, Russian comes in many different dialects. While some place the official number as high as 14, there are also several transitional dialects. The dialects can largely be grouped by the region in Russia where they are spoken.
The dialects fall into roughly three regions.
Northern Russian: Pomor, Ladoga-Tikhvin, Vologda, Kostroma-Yaroslavl
Central Russian: Western and Eastern
Southern Russian: Western, Central, Eastern
So what about those Russian dialects?
The Russian dialects mostly vary from each other in terms of pronunciation of a few letters. The vocabulary of each region and dialect also contain different archaic vocabulary based on region and when the region was settled.
The dialects can also be grouped into the primary formation and the secondary formation, which refer to when the regions of Russia were settled. The primary formation includes what is commonly referred to as “Old” Russia, which was settled during the 16th century and includes the modern Central and Northwestern Federal districts. The secondary formation refers to areas of Russia occupied after the 16th century.
Ultimately the differences in dialects mostly consist of differences in the pronunciation of certain letters and verb endings, especially for vowels. The alphabet is not drastically different for different dialects, making the numerous dialects not a significant barrier in terms of learning the Russian language.