It depends on the context,
but most likely they are the same thing.
Property tax can refer to a tax paid on different items based on
their value. This can include real
estate, vehicles, motor homes, mobile homes, boats, planes, etc.
So, real estate taxes are
property taxes that you pay based on the value of real estate.
Many times the Form 1098 from your mortgage company may not show the amount of real estate property tax paid in a particular box on the form, but it will be printed elsewhere on the page as supplemental information. This is especially true if the tax was paid through an escrow account.