Role of APIs In Salesforce

It is specialized Restful APIs in salesforce for loading and querying lots of data at once. It means we can retrieve 50,000 or more records at a time. It is asynchronous in nature. We preferred this approach when we deal with a large amount of data. We have two versions of the Bulk API (1.0 and 2.0). Both versions handle large amounts of data.

Bulk API is best when our task involves lots of records, like the loading of data into your org for the first time.

Let’s talk about Streaming API!

Streaming API is also specialized Salesforce APIs for setting up notifications that trigger when changes are made to your data. It enables the streaming of events using push technology and provides a subscription mechanism. Subscription API supports multiple types of events, generic events, platform events and Change Data Capture events.
It is best to use Streaming API for applications that require general notification of data change in an org to reduce the number of APIs in Salesforce calls and improve performance.

Push Technology – Push technology, also called publish/subscribe model. It helps to transfer information that is initiated from a server to the client. It is the opposite of pull technology. In pull technology, request for information is made from client to server.

Message Reliability- Streaming API provides reliable message delivery by enabling you to replay past events through streaming, this feature involves API version 37.0 or later. The client subscribed with API version 36 or earlier, we might not receive all messages.

Message Durability– Through Salesforce APIs version 37.0 and later you can retrieve events within the retention window through durable Streaming.

Which API should I Use When?