# Application networks and modern API concepts

*MuleSoft Developer Study Guide · Creating Application Networks · Last updated October 28, 2026 · https://www.certifyforce.com/study-guide/mulesoft-developer/creating-application-networks/application-networks-and-modern-api-concepts*

What an application network is and why each reusable API makes the next project faster, the three qualities of a modern API, how a web service differs from an API, and when an API is internal, partner or external.

- Certification: Salesforce MuleSoft Developer
- Exam section: Creating Application Networks
- Study guide: https://www.certifyforce.com/study-guide/mulesoft-developer

**Official exam objective:**

> Identify core architectural concepts of the Application Network and modern APIs.

## What the exam expects

- Pick the correct definition of an application network and reject look-alikes (a message broker, a VPN, nightly file copies).
- Explain why delivery speeds up as an application network grows: each API becomes a reusable asset for the next project.
- Name the three qualities of a modern API and spot options that contradict them.
- Separate APIs from web services: every web service is an API, not every API is a web service.
- Choose internal, partner or external access for an API from who must call it.

Key terms:
- **Application network**: applications, data and devices connected through reusable, governed APIs that other consumers can discover and use.
- **Modern API**: an API that is discoverable and accessible, productized and reusable, and managed for security and performance.
- **Web service**: a specific type of API that communicates over a network using web protocols.
- **Partner API**: an API that specific outside organizations reach with exclusive permissions.

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Application network definition | Connects applications, data and devices in a reusable, scalable, governed way | [Discover Application Networks](https://trailhead.salesforce.com/content/learn/modules/application-networks-and-api-led-connectivity-in-mulesoft/discover-application-networks) |
| Network building blocks | APIs, used as standardized, reusable building blocks instead of single-use integrations | [Discover Application Networks](https://trailhead.salesforce.com/content/learn/modules/application-networks-and-api-led-connectivity-in-mulesoft/discover-application-networks) |
| Network is not an architecture | A set of building blocks on top of which architectures are built | [What is an application network?](https://www.mulesoft.com/resources/api/what-is-an-application-network) |
| Agility measure | How many consumers get value, not how many assets exist | [What is an application network?](https://www.mulesoft.com/resources/api/what-is-an-application-network) |
| Three modern API qualities | Discoverable and accessible; productized and reusable; managed for security and performance | [Discover Application Networks](https://trailhead.salesforce.com/content/learn/modules/application-networks-and-api-led-connectivity-in-mulesoft/discover-application-networks) |
| API forms in the network | REST, SOAP and database APIs | [Discover Application Networks](https://trailhead.salesforce.com/content/learn/modules/application-networks-and-api-led-connectivity-in-mulesoft/discover-application-networks) |
| Web service vs API | All web services are APIs; not all APIs are web services | [APIs and Web Services](https://trailhead.salesforce.com/content/learn/modules/application-networks-and-api-led-connectivity-in-mulesoft/examine-apis-and-web-services) |
| SOAP transports | HTTP, and also JMS, FTP and SMTP | [APIs and Web Services](https://trailhead.salesforce.com/content/learn/modules/application-networks-and-api-led-connectivity-in-mulesoft/examine-apis-and-web-services) |
| Partner API | Specific outside organizations, exclusive permissions | [Types of APIs](https://www.mulesoft.com/api/types-of-apis) |
| External API | Third-party developers, self-service basis | [Types of APIs](https://www.mulesoft.com/api/types-of-apis) |

## Check yourself

- Why does MuleSoft say counting the assets on an application network is the wrong measure of agility?
- Why does a custom Salesforce-to-SAP integration that is on time and on budget still add no leverage?
- Which example list names XML-RPC services, and what does that list describe?
- When is an API internal rather than external?

## Sources

- [Understanding Application Networks and APIs for Innovation (Trailhead unit)](https://trailhead.salesforce.com/content/learn/modules/application-networks-and-api-led-connectivity-in-mulesoft/discover-application-networks)
- [What is an application network?](https://www.mulesoft.com/resources/api/what-is-an-application-network)
- [Understanding APIs and Web Services for Integration (Trailhead unit)](https://trailhead.salesforce.com/content/learn/modules/application-networks-and-api-led-connectivity-in-mulesoft/examine-apis-and-web-services)
- [Types of APIs and how to determine which to build](https://www.mulesoft.com/api/types-of-apis)
- [3 customer advantages of API-led connectivity](https://www.mulesoft.com/api/advantages-of-api-led-connectivity)
- [Understanding API-Led Connectivity Essentials (Trailhead unit)](https://trailhead.salesforce.com/content/learn/modules/application-networks-and-api-led-connectivity-in-mulesoft/explore-api-led-connectivity)
- [Application network (MuleSoft Blog)](https://blogs.mulesoft.com/learn-apis/application-network/)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 5 linked practice questions, and unlimited timed mock exams are included with the MuleSoft Developer pack (USD $19): https://www.certifyforce.com/practice-exams