Magento by default provides some of the really helpful factory methods to tweak the ecommerce system.
Lets say, you want to get a collection of products which are prices between INR 100-200 and have inventory more than 10. Making a SQL query and fetching information from complex EAV ( entity attributes values ) tables is definately a very sophisticated and complex task which every programmer know but know will like to do that.
Magento knows every ecommerce requirement and thus provides a very easy solution to this requirement.
$_product = Mage::getModel('catalog/product')->load($_productID);
// loads an obejct with all properties of a product with given productID.
echo $_product->getName();
//prints the name of the product.
echo $_product->getShortDescription();
// similary this prints the short Description of products.
/* Similarly we can print all the attributes of a certain product,
in case if you dont know attribute code then refer magento admin backend
(catalog->attribute->manage attributes then search for the attribute code you are looking for. */