Salesforce invokes a process on a remote system, waits for completion of that process, and then tracks state based on the response from the remote system.

Example:
A custom Visualforce page or button initiates an Apex SOAP or REST callout in a synchronous manner.

2. Remote Process Invocation—Fire and Forget
Salesforce invokes a process in a remote system but doesn’t wait for completion of the process. Instead, the remote process receives and acknowledges the request and then hands off control back to Salesforce.

Example:
a. Workflow-driven outbound messaging
b. Outbound messaging and callback
c. Custom Visualforce page that initiates an Apex SOAP or HTTP asynchronous callout

3. Batch Data Synchronization
Data stored in Lightning Platform should be created or refreshed to reflect updates from an external system, and when changes from Lightning Platform should be sent to an external system. Updates in either direction are done in a batch manner.

Example:
Leverage a third-party ETL tool that allows you to run change data capture against source data.

4. Remote Call-In
Data stored in Lightning Platform is created, retrieved, updated, or deleted by a remote system.

Example:
a. SOAP API
b. REST API
c. BULK API

5. UI Update Based on Data Changes
The Salesforce user interface must be automatically updated as a result of changes to Salesforce data.

Example:
Push Topic