def saas():
    """
    Returns a detailed summary of all important SaaS points
    extracted from the user's cloud computing notes.
    """

    summary = """
Software-as-a-Service (SaaS) — Key Points

1. Definition:
   SaaS delivers fully functional software applications over the internet on a subscription basis.
   Users access the software through a web browser without installing anything locally.

2. Responsibility Split:
   - Cloud Provider manages: entire application, infrastructure, servers, updates,
     security, data handling, and maintenance.
   - Cloud Consumer manages: only the usage of the software.
   This gives consumers zero administrative responsibility.

3. Characteristics:
   - Accessible from any device with internet access.
   - Requires no installation or hardware setup.
   - Software is maintained and updated by the provider.
   - Subscription-based or pay-per-use pricing.
   - Supports multi-device accessibility.

4. Purpose:
   Used when users need direct access to applications without technical knowledge
   or infrastructure management.

5. Functionality:
   SaaS applications are delivered as ready-to-use products for business or personal use.

6. Typical use cases:
   - Email services.
   - Office productivity tools.
   - Customer relationship management (CRM).
   - File storage and collaboration platforms.

7. Example from notes:
   A wildlife photographer renting Adobe’s high-end photo editing software through SaaS
   because purchasing it is too costly.

8. Role in Cloud Hierarchy:
   SaaS is the highest abstraction layer in the cloud model.
   Everything below (PaaS and IaaS) is hidden from the consumer.

9. Providers:
   Google Workspace, Microsoft Office 365, Adobe Creative Cloud.
    """

    return summary
