In computer science, a thread is the smallest unit of processing that can be performed within an operating system.
One thread can perform one "task" in Grooper. This allows for concurrent processing of multiple tasks. For example, if your system has 8 threads available, and the Recognize activity is set to the Page level Scope, the activity will run on 8 pages at a time. If your system only has 2 threads available, only 2 pages will be processed. If you have 64 threads, 64 pages will be processed at a time.
You can control how many threads are used to process an Activity using the Tread Pool object and installing the Activity Processing service in Grooper Config.