The Collect block receives individual data items from iterations of a loop, then aggregates them into a list, formatted as a JSON array like this: ["item1","item2","item3"]. For example, if a loop sends one HTTP request per iteration, the Collect block can gather all the responses into a single list when the loop completes. The Collect block is commonly used with the For block, which sends each item in a list individually, and the Repeat block, which runs a group of blocks multiple times.
Item - Accepts a single data item from a For or Repeat loop.
List - Creates a JSON array of all the items sent to this block when the loop is complete.
Finish - Sends an event when the loop is complete and the Collect block has aggregated the data into an array.
To see the Collect block in an example flow, check out Flow Snippets: Collect.
For more information about creating loops in Flows and tutorials that use the Collect block, see the following: