SaaS ('software as a service', which is also called 'on-demand software') is a business-to-business service favored by countless companies worldwide. Such software is based on a shared infrastructure, and is maintained by its owners. Small and medium businesses may see SaaS as an opportunity to use software in the most cost-saving way. The same software is used by numerous clients, while cloud hosting, technical support and updates are carried out rapidly and efficiently, and transparent for the