Almost all foreclosure types have some complication to them. Tax foreclosures can come in the manner of property taxes, state taxes, or federal government taxes. Anytime you do not pay your taxes the governmental body can place a lien on your home and foreclose on the property to get their monies.
A bank foreclosure is the same idea except the bank forecloses after mortgage payments have been missed. The main difference between a tax foreclosure and a bank foreclosure is that the government gets their money first. When the house is sold the money goes to the government first for back taxes and then any monies left over go to the next lien holder, then the next, until it all the proceeds from the sale are gone.
The issue is, if there are not enough monies from the sale to pay off all the lien holders, the lien holders may be able to come after private monies and property. (i.e. car) Some loans are called "recourse" loans and in that case the lien holder can come after personal holdings to get their monies. See your tax or legal professional to review the situation and for specific advice.