There are varying degrees to which you can enable/implement localization/internationalization. In simplest form, you can use google translate to translate page in multiple languages. This is far from perfect approach. Alternately, a multi-language enabled website will allow you to enter translations. There is more to it than that. What about text in graphics/images? Same thing applies to currency. In simplest form one can convert currency from USD to local current using a conversion rate. But for a global company, the price at which you may want to sell in US market vs Europe may be different. The taxes/VAT may be different. UK/Europe stores display prices including VAT. To summarize, for a good implementation, consult a localization and internationalization expert.
Inventory Control Management
Table Rate Shipping
Product (Stocked/Kit) Management
Customized Product Detail Page with Custom Attributes