For the most part, all assets and debts that were acquired during the marriage are subject to equitable distribution. Equitable does not necessarily mean "50/50" split, it means equitable or in other words, what is fair. There are some very detailed and defined exceptions such as inheritances and passive appreciation. The presumption under Florida Statute 61.075 is that the division be equal. It doesn't matter under whose name the asset is under, or which party incurred the debt.
If the one spouse incurs a $50,000.00 debt during the time the parties were married, equitably speaking the other spouse in liable for half of that debt. In a very real sense the law looks at a married couple as one entity.
An asset that was acquired before the marriage is considered non-marital and is possibly not subject to equitable distribution. Whoever if this asset is brought into the marriage it may become susceptible to distribution. For example, if Grandma left one party a million dollar inheritance prior to the marriage and it was always kept in a separate account, it may be considered non-marital. However, if Grandma's inheritance was brought into the marriage and the party used it to pay the mortgage for the marital home, pay for vacations for the both parties and put into a joint account to pay bills, it may be then considered a marital asset and now it may be a part of equitable distribution during the divorce proceedings.