New York is an "equitable property" state. This means that any property, asset and/or debt accrued during your marriage is considered marital property, and therefore subject to distribution between parties.
"Equitable", otherwise known as "fair", means that the court will use its discretion to determine how and to whom property will be distributed. Some examples of marital property are as follows: homes and other real estate properties, retirement plans (pension, 401(k), etc.), professional degrees and licenses, art, decor and other personal property, as well as cars, boats, RVs, etc. (this is a non-exhaustive list).
Additionally, the "appreciation" in value of some separate property may also be distributed to the non-title-holding spouse, if s/he can prove sufficient direct/indirect efforts which allowed the appreciation to occur. And because any distribution done by the Court must be "equitable," this means in some case it is 50% but in other cases the court could use a higher (60+%) or lower (0-40%) percentage.
Moreover, the Court may distribute some assets (like a house or bank account) 50%, and other assets (like the value of a degree) only 10-20% within the same case.