Many companies have turned to virtualization technologies for their servers and in their data centers. Doing so has allowed them both to simplify administration and to reduce management chores and operating costs, while maintaining reliability and safeguarding against disasters. Seeing the significant benefits virtualization delivers in those environments, companies are now looking to apply the same technology to their desktop computers. This paper explores and compares the three different types of virtualization, with a focus on the concept and benefits of a VDI (Virtual Desktop Infrastructure).