FC0-U61 Objective 3.4: Explain Methods of Application Architecture and Delivery Models

September 16, 2025•18 min read•CompTIA IT Fundamentals

FC0-U61 Exam Focus: This objective covers how applications are delivered to users and the different architectural models used to build applications. Understanding application delivery methods and architecture models is essential for anyone working with software, as it affects how applications are accessed, where data is stored, and how systems are designed. This knowledge is crucial for making informed decisions about software deployment, understanding system requirements, and troubleshooting application issues.

Understanding Application Delivery and Architecture

Applications can be delivered to users in different ways, and they can be built using various architectural models. The delivery method determines how users access the application, where the application runs, and how data is stored. The architecture model defines how the application is structured internally, including how different components interact and where processing occurs. Understanding these concepts is essential for selecting appropriate solutions and understanding system requirements.

Application Delivery Methods

What Are Application Delivery Methods?

Application delivery methods refer to how applications are made available to users and where they are hosted. The choice of delivery method affects performance, accessibility, maintenance, security, and cost. Different delivery methods have different requirements for network connectivity, hardware resources, and user access patterns. Understanding these methods helps in selecting the most appropriate approach for specific use cases and requirements.

Locally Installed

Locally installed applications are installed directly on the user's computer:

Locally Installed Characteristics:

Installation: Application is installed on the local computer
Execution: Application runs on the local machine
Storage: Application files stored on local storage
Performance: Direct access to local hardware resources
Offline capability: Can run without network connection
Customization: Can be customized for specific hardware
Security: Data and processing remain on local machine
Maintenance: Updates must be installed on each machine

Network Not Required

Locally installed applications can run without network connectivity:

Offline Benefits:

Reliability: Works even when network is unavailable
Performance: No network latency or bandwidth limitations
Privacy: Data processing happens locally
Security: No data transmission over networks
Independence: Not dependent on external services
Consistency: Performance is consistent regardless of network conditions

Application Exists Locally

The application and its components are stored on the local machine:

Local Storage Benefits:

Fast access: Immediate access to application files
No download time: No need to download application each time
Version control: Specific version installed and maintained
Customization: Can be customized for specific system
Integration: Can integrate with local system resources
Backup: Can be backed up with system backup

Files Saved Locally

User data and files are stored on the local machine:

Local File Storage:

Data control: User has complete control over their data
Privacy: Data remains on user's machine
Access speed: Fast access to local files
Backup responsibility: User responsible for data backup
Storage limits: Limited by local storage capacity
Portability: Data tied to specific machine

Local Network Hosted

Applications are hosted on a local network server and accessed by network clients:

Network Required

Local network hosted applications require network connectivity:

Network Dependencies:

Connectivity requirement: Must be connected to local network
Network performance: Performance depends on network speed
Network reliability: Network outages affect application access
Bandwidth usage: Network traffic for application access
Latency: Network latency affects response times
Security: Network security affects application security

Internet Access Not Required

Local network hosted applications don't require internet connectivity:

Local Network Benefits:

Internet independence: Works without internet connection
Security: No exposure to internet threats
Performance: No internet bandwidth limitations
Privacy: Data stays within local network
Control: Complete control over network environment
Reliability: Not affected by internet outages

Cloud Hosted

Applications are hosted on remote cloud servers and accessed over the internet:

Cloud Hosted Characteristics:

Remote hosting: Application runs on cloud servers
Internet access: Accessed via web browsers or clients
Scalability: Can scale resources based on demand
Global access: Accessible from anywhere with internet
Managed services: Infrastructure managed by cloud provider
Automatic updates: Updates applied automatically by provider
Backup and recovery: Managed by cloud provider
Cost model: Pay-per-use or subscription pricing

Internet Access Required

Cloud hosted applications require internet connectivity:

Internet Dependencies:

Connectivity requirement: Must have internet connection
Bandwidth requirements: Sufficient bandwidth for application use
Latency considerations: Internet latency affects performance
Reliability dependency: Internet outages affect access
Security considerations: Data transmitted over internet
Geographic factors: Distance from servers affects performance

Service Required

Cloud hosted applications require ongoing service from the provider:

Service Dependencies:

Provider availability: Dependent on service provider uptime
Service level agreements: Performance guarantees from provider
Support services: Technical support from provider
Maintenance windows: Scheduled maintenance by provider
Feature updates: New features provided by service
Compliance: Provider must meet compliance requirements

Files Saved in the Cloud

User data and files are stored on cloud servers:

Cloud Storage Benefits:

Accessibility: Access files from anywhere with internet
Backup and recovery: Automatic backup and recovery
Collaboration: Easy sharing and collaboration
Scalability: Storage can grow as needed
Sync across devices: Files sync across multiple devices
Version history: Automatic version control and history

Application Architecture Models

What Are Application Architecture Models?

Application architecture models define how applications are structured internally, including how different components are organized and how they interact. The architecture model affects performance, scalability, maintainability, and security. Understanding these models helps in designing applications, troubleshooting issues, and making decisions about system architecture. Different models are suitable for different types of applications and requirements.

One Tier (Monolithic)

One tier architecture combines all application components in a single layer:

One Tier Characteristics:

Single layer: All components in one application
User interface: Integrated with business logic and data
Data storage: Embedded within the application
Deployment: Single deployment unit
Development: Simple development and testing
Performance: Fast execution with no network overhead
Scalability: Limited scalability options
Maintenance: Changes require full application update

One Tier Advantages:

Simplicity: Simple to develop and deploy
Performance: Fast execution with no network latency
Reliability: No network dependencies
Security: All components in one secure environment
Cost: Lower infrastructure costs
Development speed: Faster initial development

One Tier Disadvantages:

Scalability: Difficult to scale individual components
Maintenance: Changes affect entire application
Technology lock-in: Limited technology choices
Resource usage: All resources on single machine
Fault tolerance: Single point of failure
Team collaboration: Difficult for large development teams

Two Tier (Client-Server)

Two tier architecture separates the application into client and server components:

Two Tier Characteristics:

Client layer: User interface and presentation logic
Server layer: Business logic and data storage
Network communication: Client and server communicate over network
Data access: Client requests data from server
Processing distribution: Processing split between client and server
Deployment: Separate client and server deployments
Scalability: Server can serve multiple clients
Maintenance: Can update client and server independently

Two Tier Advantages:

Scalability: Server can handle multiple clients
Centralized data: Data stored centrally on server
Security: Centralized security on server
Resource sharing: Multiple clients share server resources
Data consistency: Single source of truth for data
Backup: Centralized backup on server

Two Tier Disadvantages:

Network dependency: Requires network connectivity
Server bottleneck: Server can become performance bottleneck
Client complexity: Clients need to handle business logic
Deployment complexity: Must deploy to multiple clients
Version management: Managing client versions can be complex
Network latency: Network latency affects performance

Three Tier

Three tier architecture separates the application into presentation, business logic, and data layers:

Three Tier Characteristics:

Presentation tier: User interface and user interaction
Business logic tier: Application logic and business rules
Data tier: Data storage and data access
Separation of concerns: Each tier has specific responsibilities
Independent scaling: Each tier can be scaled independently
Technology flexibility: Different technologies for each tier
Maintainability: Changes in one tier don't affect others
Security: Security can be implemented at each tier

Three Tier Advantages:

Scalability: Each tier can be scaled independently
Maintainability: Easier to maintain and update
Flexibility: Can use different technologies for each tier
Performance: Optimized for each tier's specific function
Security: Security implemented at appropriate levels
Team development: Different teams can work on different tiers

Three Tier Disadvantages:

Complexity: More complex than one or two tier
Network overhead: Multiple network communications
Deployment complexity: Must deploy and manage multiple tiers
Latency: Multiple network hops increase latency
Cost: Higher infrastructure costs
Management: More complex system management

N-Tier+ (Multi-Tier)

N-tier architecture extends three tier with additional specialized layers:

N-Tier Characteristics:

Multiple tiers: More than three specialized layers
Specialized functions: Each tier has specific purpose
Service-oriented: Tiers can provide services to other tiers
Microservices: Can include microservice architecture
Cloud-native: Designed for cloud environments
API layers: API gateways and service layers
Caching layers: Dedicated caching and performance tiers
Integration layers: Enterprise integration and messaging

Common N-Tier Layers

Additional Tiers:

API Gateway: Entry point for external requests
Load Balancer: Distributes requests across servers
Cache Layer: Improves performance with caching
Message Queue: Asynchronous communication between tiers
Integration Layer: Connects with external systems
Security Layer: Authentication and authorization
Monitoring Layer: System monitoring and logging
Service Layer: Business services and microservices

N-Tier Advantages:

High scalability: Each tier can be scaled independently
Flexibility: Maximum flexibility in architecture
Performance: Optimized for specific functions
Reliability: High availability and fault tolerance
Cloud-ready: Designed for modern cloud environments
Enterprise features: Advanced enterprise capabilities

N-Tier Disadvantages:

High complexity: Very complex architecture
High cost: Expensive infrastructure and management
Network overhead: Multiple network communications
Management complexity: Complex system management
Development time: Longer development and testing time
Expertise required: Requires specialized knowledge

Architecture and Delivery Model Comparison

Choosing the Right Model

Selection Criteria:

Application type: Different applications suit different models
User requirements: Consider user access patterns and needs
Scalability needs: Current and future scalability requirements
Performance requirements: Response time and throughput needs
Security requirements: Data sensitivity and security needs
Budget constraints: Infrastructure and maintenance costs
Technical expertise: Available technical skills and resources
Integration needs: Requirements for system integration

Model Combinations

Different delivery methods can be combined with different architecture models:

Common Combinations:

Locally installed + One tier: Desktop applications
Local network + Two tier: Traditional client-server applications
Cloud hosted + Three tier: Web applications
Cloud hosted + N-tier: Enterprise cloud applications
Hybrid models: Combination of local and cloud components
Multi-cloud: Applications spanning multiple cloud providers

Modern Trends and Considerations

Cloud-Native Applications

Cloud-Native Features:

Microservices: Small, independent services
Containerization: Docker and Kubernetes deployment
Serverless: Function-as-a-Service (FaaS) models
API-first: APIs as primary interface
DevOps integration: Continuous integration and deployment
Auto-scaling: Automatic resource scaling

Hybrid and Multi-Cloud

Hybrid Considerations:

Data sovereignty: Keeping sensitive data on-premises
Performance optimization: Using cloud for scalability
Cost optimization: Balancing cloud and on-premises costs
Compliance: Meeting regulatory requirements
Disaster recovery: Backup and recovery strategies
Integration complexity: Managing hybrid environments

Exam Preparation Tips

Key Concepts to Master

Delivery methods: Understand locally installed, local network, and cloud hosted
Architecture models: Know one tier, two tier, three tier, and n-tier
Characteristics: Understand the characteristics of each model
Advantages and disadvantages: Know the pros and cons of each approach
Use cases: Understand when to use each model
Network requirements: Know network dependencies for each model

Study Strategies

Effective Study Approaches:

Model comparison: Create tables comparing different models
Scenario mapping: Map scenarios to appropriate models
Diagram creation: Draw diagrams of different architectures
Real-world examples: Study actual applications and their architectures
Network analysis: Understand network requirements for each model
Trade-off analysis: Understand the trade-offs between different approaches

Practice Questions

Sample Exam Questions:

What delivery method requires internet access but not local network?
What architecture model combines all components in a single layer?
What delivery method stores files locally on the user's machine?
What architecture model separates presentation, business logic, and data?
What delivery method requires local network but not internet access?
What architecture model can include microservices and API gateways?
What delivery method provides automatic updates and managed services?
What architecture model separates client and server components?
What delivery method allows offline operation without network connectivity?
What architecture model provides the highest scalability and flexibility?

FC0-U61 Success Tip: Understanding application delivery methods and architecture models is essential for making informed decisions about software deployment and system design. Focus on learning the characteristics, advantages, and disadvantages of each delivery method (locally installed, local network hosted, cloud hosted) and architecture model (one tier, two tier, three tier, n-tier+). Pay special attention to network requirements, scalability considerations, and use cases for each approach. This knowledge is crucial for understanding system requirements, troubleshooting application issues, and selecting appropriate solutions for different scenarios.

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