This is the 7453rd most frequent Russian word.
дв
"Дв" is not a standalone word in Russian but could be an abbreviation or part of a word. Clarification is needed.
In this sentence, 'два' is the number 'two' and is used to count masculine or neuter nouns.
У нас в группе два человека.
There are two people in our group.
Here, 'вдвоём' is a form derived from 'два', meaning 'together' (literally, 'as two').
Давайте попробуем сделать это вдвоём.
Let's try to do this together.
The word 'двух' is the genitive form of 'два' used in this context to show ownership or relation with the noun it modifies.