Glossary
This glossary defines common terms used throughout the RunAtlas cloud platform.
A
- Account: The administrative entity that owns resources (instances, networks, volumes) and is billed monthly.
- Availability Zone (AZ): Isolated data center location within a Region designed to minimize failure impact.
C
- Cluster: A group of Host nodes (physical servers) managed as a single pool of resources.
- Compute Offering: defines CPU and RAM allocations for an Instance (e.g., Small, Medium, Large).
- Core: A virtual CPU (vCPU) allocated to an instance.
D
- Disk Offering: Defines the size and performance characteristics (IOPS) of a Data Volume.
- Data Volume: Additional storage attached to an instance, separate from the Operating System (Root) disk.
E
- Elastic IP (EIP): A static public IP address that can be remapped between instances.
- Egress Rule: Firewall rule controlling outbound traffic from a network.
G
- Guest Network: An isolated virtual network (VLAN/VXLAN) dedicated to a single account.
- Gateway: The router interface providing connectivity for a network.
H
- Host: Physical server running the hypervisor (KVM) where instances reside.
- Hypervisor: Software (KVM) that creates and runs virtual machines.
I
- Image / Template: A pre-configured operating system image (e.g., Ubuntu, CentOS) used to launch instances.
- Instance: A Virtual Machine (VM).
- Ingress Rule: Firewall rule controlling inbound traffic to a network.
K
- Key Pair: SSH public/private keys used for secure instance authentication.
N
- Network: The connectivity layer (L2/L3) for instances. See Guest Networks.
- Network ACL: Stateless firewall rules operating at the subnet level in a VPC.
P
- Port Forwarding: Mapping an external public port to an internal private IP/port.
- Public IP: A globally routable IPv4 address.
- Project: A logical grouping of resources and users for collaborative management.
R
- Region: A geographic area containing multiple Availability Zones.
- Root Volume: The primary disk containing the OS of an instance.
- Router (Virtual Router): A system VM managing network services (DHCP, DNS, NAT, VPN, Firewall) for a Guest Network.
S
- Security Group: Stateful firewall rules applied directly to an instance’s network interface.
- Snapshot: A point-in-time backup of a Volume.
- Source NAT: The primary public IP used for outbound traffic from a private network.
- Static NAT: 1-to-1 mapping of a Public IP to a Private IP.
T
- Template: System image used to create new VMs.
- Tier: A logical subnet within a VPC (e.g., Web Tier, App Tier).
U
- User Data: Scripts or cloud-init configuration passed to an instance at launch.
V
- VLAN: Virtual Local Area Network; L2 isolation mechanism.
- VM: Virtual Machine; see Instance.
- Volume: A virtual hard disk (standard or SSD).
- VPC (Virtual Private Cloud): An isolated network environment with user-defined subnets, routes, and gateways.
- VPN: Virtual Private Network; secure connection logic.