A Chapter 7 bankruptcy is when you have limited assets and are seeking for a total discharge of your debt obligations. There are certain limitations associated with filing a Chapter 7, such as how much assets you can have.
A Chapter 13 bankruptcy is what most people use to stop a foreclosure. A Chapter 13 is also known as a reorganization bankruptcy, in which you agree to repay your creditors in a specified schedule up to the limit of your ability. For example, if your obligation requires you to pay back $1,000 a month but your maximum amount that you can pay back is only $200, then all you are obliged to pay is $200 for the term of the bankruptcy (usually between 3 and 5 years). After that period, all your debt is discharged.