As anyone who has ever purchased a used car will tell you, looks can be deceiving. To get a true picture of the quality of the product, you have to "look under the hood".
What does this have to do with shopping for a new home?
When you find a property you like on the market, it's easy to fall in love with it's appearance and features. However, there may be issues you won't notice, such as foundation cracks or a furnace that is is due for replacement.
That is why you need to "look under the hood" by having a qualified home inspector review the property.