The inspection of a properties foundation is one of the most crucial steps during the inspection process.  A structural defect can cost thousands to repair, and even then, the repair may not be guaranteed by the repairing company.  It is crucial that your inspector is well educated on the construction of a foundation and what the signs of a poorly performing foundation can cause.
The myth, for most people, is a crack in interior drywall or on the exterior brick indicates a foundation problem.  This is NOT true.  Cracking is an indication of foundation settlement, but does not mean that a home is going to fall down.  Major foundation issues are not always visible.  Did you know that major foundation problems will cause issues in the roof framing of home?  An good inspector knows where to look for indications of major foundation problems and can usually refer you to a specialist to who is qualified to make these repairs.  So, just because you see a crack, don't panic, hire an inspector to evaluate your property, it could save you thousands in unnecessary repairs or could save you from buying the next "Leaning Tower of Pisa".