We also distinguish several models of cloud computing:
- the best-known:
IaaS (Infrastructure as a Service)
PaaS (Platform as a Service)
SaaS (Software as a Service)
there are also CaaS and IPaaS.

IaaS - a model based on providing the client with IT infrastructure, i.e., hardware, software, and service. For example, a client buys a specific number of servers, disk space or a particular memory resource and computing power. This does not mean, however, that the equipment will be physically installed at the customer's premises.
PaaS - sale of ready, often tailored to the needs of the user, a set of applications. It does not involve the need to purchase equipment or install software. All necessary programs can be found on the provider's servers. The customer on his side has access to the interface, for example via a web browser. In this model, services are most often available to the user from any computer connected to the Internet.
SaaS - the client receives specific, selected software functions. He uses the software he needs. He is not interested in equipment or the work environment. He only has access to accurate, functional tools - not necessarily connected with one another interface. The programs operate on the provider's server. The customer is not forced to acquire a license for them. He pays only for each user, and access to them is available on demand