Website
A website usually focuses on information, discovery and public interaction. It can contain forms and dynamic content without becoming an operational system.
Platform
A platform connects multiple user types or services in an ongoing experience and often needs accounts, permissions, data and multiple workflows.
Internal system
An internal system supports staff workflows such as requests, customers or reporting. Its success is measured by clearer operations and less manual work, not visual design alone.
Before starting a project
Use these questions to structure the idea, then send what you have. You do not need a complete technical specification before contacting SDS.