Being a country in the Victorian age is not something you will ever get envy for. After all, the whole era was named after a single ruler, so it goes without saying that not every country was equal.
All in all, there are six different ranks that a country can occupy in Victoria 3, as well as a special seventh rank that only applies to Decentralized, non-playable, nations.
First off, we have the Great Powers. These are the most powerful and glorious of nations and often have a global reach, getting involved in far-off conflicts. The most obvious example of a Great Power at the start of the game is Great Britain.
Following closely by are the Major Powers, which are regional powerhouses that often decide the course of conflicts in their home regions and may have a limited global presence. An example of a Major Power at the start of the game is the Kingdom of the Two Sicilies.
After that, Victoria 3 has the Minor Powers. These are regional powers that may be important for determining how a local conflict in their home region turns out but are generally irrelevant on the world stage. An example of a Minor Power at the start of the game is Mexico.
The most numerous countries in the world ar, by far, those that are at Insignificant Power levels. These are nations that generally do not even have the ability to influence the outcome of local conflicts and can be safely ignored by anyone other than other Insignificant Powers in their immediate vicinity. An example of an Insignificant Power at the start of the game is the Free City of Krakow.
Unrecognized Power is a moniker given to countries that are powerful and prestigious enough to throw their weight on a regional stage, try to resist the demands of the Recognized powers, and be a potential candidate for recognition. An example of an Unrecognized Power at the start of the game is the Qing Empire.
Unrecognized Minor Powers, however, are the poor and downtrodden countries that generally lack the power to go up against anyone other than the weakest of Recognized powers, and will often find themselves at the mercy of Great and Major Powers and having to play them against each other to survive. An example of an Unrecognized Minor Power at the start of the game is the Kingdom of Nepal.