Though both languages are considered Indo-European but of different groups. Russian and Romanian are very different, they belong to two different language groups, the former being a slavic language, the latter a romance language with a strong latin imprint (it is the only romance language that maintains the latin declension).
The two languages are not in the same family of languages. Romanian uses the Latin alphabet. Whereas Russian is a Slavic language and written using the Cyrillic alphabet.
As any other language, also Romanian was subject to linguistic influences through the centuries (German, French, Slavic, Turkish, Greek influences). However, even if a person speaks and understands Romanian pretty well, you cannot say that he understands Russian as well or that listening to it he can get a sense of it.
Russian is closer to other Slavic languages such as Polish, Czech, Serbo-Croatian, Slovak, and Bulgarian, but even more specifically East Slavic languages like Ukrainian and Belarusian.Romanian is closer to other Romance (Latin based) languages like French, Spanish, and Portuguese, with Italian probably being the closet.
Here are some things unique in Romanian that other Romance languages don’t have:
‘’U’’ instead of ‘’o’’
Many related words of Romance languages containing the letter ‘’o’’ will have a ‘’u’’ instead in Romanian.
Ear
Italian: orecchio
Spanish: oreja
Portuguese: orelha
French: oreille
Romanian: ureche
No
Italian: no
Spanish: no
Portuguese: não
French: non
Romanian: nu
But sometimes, this actually makes the Romanian word sound closer to Latin than the counterpart words:
One
Latin: unus
Italian: uno
Spanish: uno
Portuguese: um
French: un
Romanian: unu
Let’s also consider Member:
Latin: membrum
Italian: membro
Spanish: miembro
Portuguese: membro
French: membre
Romanian: membru
