O'Reilly Answers is a community site for sharing knowledge, asking questions, and providing answers that brings together our customers, authors, editors, conference speakers, and Foo (Friends of O'Reilly). More »
Grand Central Dispatch, or GCD for short, is a low-level C API that works with block objects. The real use for GCD is to dispatch tasks to multiple cores without making you, the programmer, worry abou...
Block objects are packages of code that usually appear in the form of methods in Objective-C. In this excerpt from Concurrent Programming in Mac OS X and iOS the author speaks to their purpose and use...