The theme of this graduate thesis is the virtualization of the computer network and its individual elements, namely the servers in the network. The Raspberry Pi 4 Model B platform with virtualization software, VMware ESXi hypervisor is used in this paper. Although the term virtualization has been mentioned since the 1960 s, when the IBM first introduced it, it achieved its true application and significance of virtualization only a few years back. We can say that virtualization has mainly contributed to the development of today's Cloud, or cloud computing. We can divide our work into two parts. In the first part we will mention the beginnings and types of virtualization and its advantages in relation to traditional computer architecture. The second part deals with practical work on which the acquired knowledge in the field of virtualization was applied.