What is Magento? Why use MAGENTO?

What is Magento? is it open-source software and free to download? Magento is an open source PHP was built with help programmers can create e-commerce sites. Magento was released on 31/3/2008 by Varien and it is developed on the basis of the Zend Framework. Magento is 100% free to download, you can get it here