Basic Concepts

Before using a DeH, you need to understand the following basic concepts.

Glossary	Description
BYOL	BYOL indicates the Bring Your Own License mode. If you have an OS or a software license (a license whose certified items include number of physical sockets and physical cores), you can migrate your services to the cloud platform and continue to use your existing licenses.
Region	Regions are defined by their geographical location and network latency. Public services, such as Elastic Cloud Server (ECS), Elastic Volume Service (EVS), Object Storage Service (OBS), Virtual Private Cloud (VPC), Elastic IP (EIP), and Image Management Service (IMS), are shared within the same region. There are universal regions and dedicated regions. A universal region serves all tenants, while a dedicated region serves specific tenants.
Availability zone (AZ)	An AZ contains one or multiple physical data centers. Each AZ has independent cooling, fire extinguishing, moisture-proof, and electricity facilities. Within an AZ, computing, network, storage, and other resources are logically divided into multiple clusters. AZs within a region are interconnected using high-speed optical fibers to allow you to build cross-AZ high-availability systems. NOTE: For more information, see Region and AZ.
Project	A project groups and isolates IaaS OpenStack resources, such as compute, storage, and networking resources. A project can be a department or a team. Multiple projects can be created under one account.
DeH flavor	A DeH flavor specifies the DeH attributes, including the number of CPUs on the physical server (the number of sockets), number of physical cores, CPU model, memory size, and number of vCPUs.
Elastic Cloud Server (ECS)	ECS is a basic cloud computing service provided by Huawei Cloud. For details, see ECS.