Magento is available both as an Open Source product called “Community Edition” that is available for free and also as the commercial “Enterprise Edition”. It is used my many hundreds of thousands of stores with the Community Edition being targeted at developers, store owners with good technical knowledge or those will to employ consultants as no support is provided directly although community support is available via their public forums
Magento comes with a basic theme but there are a large number of different themes available, some free and some commercial, that can simply be uploaded and applied via the backend admin system. Modules or plugins which extend the functionality of the core product are also available and these can be used to add or modify the core functionality in almost any way that you can imagine.
It is often believed that Magento requires a dedicated server to run properly and while larger and busy stores will certainly require one, our years of E-Commerce hosting expertise has allowed us to configure Magento Hosting plans on what we call Shared Dedicated Servers which only host a handful of Magento sites.