"This is Moscow."
Москва is the nominative ending, used when it's the subject of the sentence.
Москве is the prepositional case ending, used to indicate location after в or на: Она в Москве. = She is in Moscow. There are two videos about the prepositional at: https://youtu.be/kyat8rMHubI and https://youtu.be/Vij7y-3nxRo
The trick is that in this case, "this" is a pronoun. "This is Moscow". "He is there" "That is Germany". In these cases, это is not changed. However, when I say "this case" or "that case", I'm specifying the noun ("case") with an adjective, "this", thus это must match in gender and number.
I understand that there is a literal difference in meaning between "This is Moscow" and "Here is Moscow". But is there really a semantic difference when it comes to how one would translate that into English? How would Russians use the two expressions, "Это Москва" and "Вот Москва", differently? Or can they be used interchangeably?