# Core Concepts

Understanding these core concepts will help you make the most of the DanubeData platform.

## Projects (Teams)

**Projects** (also called Teams) are the top-level organizational unit in DanubeData.

- All resources belong to a project
- Users can be members of multiple projects
- Each project has its own billing
- Resources cannot be shared between projects

### Use Cases
- Separate production and development environments
- Isolate customer resources (for agencies)
- Organize by department or team

## Resources

**Resources** are the billable components you create on DanubeData:

### Database Instances
Managed database servers (MySQL, PostgreSQL, MariaDB) with:
- Automated backups
- High availability options
- Read replicas
- Custom parameter groups

### Cache Instances
Managed Redis, Valkey, and Dragonfly with:
- Data persistence
- Replication
- Automatic failover
- Memory optimization

### VPS Instances (Pods)
Virtual private servers with:
- Multiple OS options
- SSH access
- Custom resource profiles
- Snapshot capabilities

### Storage Volumes
Persistent storage that can be attached to instances:
- NVMe storage (high performance)
- Block storage (flexible)
- Snapshot and restore

### Object Storage
S3-compatible buckets with per-team isolation, access keys, versioning, and lifecycle rules.

### Serverless Containers (Rapids)
Scale-to-zero containers deployed from an image, Git repo, or ZIP upload.

### Static Sites
Managed builds and hosting with custom domains and free TLS.

### Queues
Managed RabbitMQ message brokers.

### Managed Apps
One-click applications, plus dedicated Storage Share (Nextcloud) and Immich offerings.

### Container Registry
A private per-team registry for your Docker/OCI images.

## Resource Profiles

**Resource Profiles** define the compute and memory specifications:

- **Micro**: 1 vCPU, 1GB RAM - Perfect for development
- **Small**: 2 vCPU, 2GB RAM - Small production workloads
- **Medium**: 4 vCPU, 4GB RAM - Medium production workloads
- **Large**: 8 vCPU, 8GB RAM - Large production workloads
- **Extra Large**: 16 vCPU, 16GB RAM - High-performance workloads

## Regions & Data Centers

DanubeData operates from a single datacenter:

- **fsn1**: Falkenstein, Germany

All resources are provisioned in this location.

## Networking

### Private Networks
Secure, isolated networks for your instances to communicate:
- No internet exposure
- Low latency
- Free internal traffic

### Firewalls
Control inbound and outbound traffic:
- Rule-based access control
- IP whitelisting
- Port management
- Can be attached to multiple instances

### Public IPs
Each instance can have a public IP address for external access.

## Backups & Snapshots

### Automated Backups
- Daily backups of databases and cache instances
- Retention: 3 days
- Point-in-time recovery

### Manual Snapshots
- On-demand snapshots of any instance
- Kept until manually deleted
- Can be used to create new instances

## High Availability

### Read Replicas
Create read-only copies of your database:
- Offload read queries
- Reporting without impacting the primary
- Automatic synchronization

### Multi-Node Setup
Deploy instances across multiple nodes for redundancy:
- Automatic failover
- Zero-downtime maintenance
- Increased reliability

## Monitoring & Metrics

Track your infrastructure with:
- **CPU Usage**: Monitor compute resources
- **Memory Usage**: Track RAM utilization
- **Disk I/O**: Measure storage performance
- **Network Traffic**: Monitor bandwidth usage
- **Database Queries**: Track query performance

## Billing

### Hourly Billing
Pay only for what you use:
- Resources are billed hourly
- Invoices generated monthly
- No long-term commitments

### Resource Costs
- Compute (vCPU and RAM)
- Storage (per GB)
- Backups (per GB)
- Network egress (per GB)

## API & Automation

Automate your infrastructure with:
- RESTful API
- API tokens for authentication
- Programmatic resource management
- Integration with CI/CD pipelines

## Security

### Authentication
- Password-based login
- Passkeys (WebAuthn) and Google/GitHub social login
- Two-factor authentication (2FA)
- SSH key authentication (for VPS)

### Encryption
- Data at rest encryption
- TLS/SSL for data in transit
- Encrypted backups

### Access Control
- Project-based permissions
- Team member roles
- API token management

## Account Limits

Default limits to prevent abuse:
- **VPS Instances**: 3 per project
- **Database Instances**: 5 per project
- **Cache Instances**: 5 per project

Limits can be increased by contacting support.

## Support

Support is included for every account at no extra cost:

- Documentation and guides
- Support tickets through the dashboard, or email support@danubedata.ro

## Next Steps

- [Deploy your first database](https://docs.danubedata.ro/databases-overview)
- [Set up networking](https://docs.danubedata.ro/networking-overview)
- [Configure monitoring](https://docs.danubedata.ro/monitoring-overview)
- [Learn about pricing](https://docs.danubedata.ro/billing-pricing)