What is the role and purpose of the autorelease mechanism in memory management in Objective-C?

The autorelease mechanism in Objective-C is used to simplify memory management of objects. When an object receives the autorelease message, it is placed into a special autorelease pool. This means that the object will be automatically released (by calling release) later, when the pool is drained, usually at the end of the current event loop.

This allows avoiding the need to manually call release immediately after using the object, easing the management of object lifetimes and preventing memory leaks. It is especially useful when creating temporary objects that are only needed within the current context.

Example:

NSObject *obj = [[NSObject alloc] init];
[obj autorelease];
// obj will be automatically released later when the pool is drained

Thus, autorelease helps balance retain and release calls without explicit management at each code location.