?? Invoke() – Synchronous Runs the method on the UI thread (or target thread) and waits until the method finishes executing.Blocking call – it halts the calling thread until the called method completes.Ensures safe UI updates from a background thread.Syntax (Windows Forms Example): this.Invoke(new Action(() => {label1.Text = "Updated from Invoke"; })); Use case: When you need to update UI controls from a background thread and want to wait until the update is complete.? BeginInvoke() – Asynchronous Starts the method on the UI thread (or target thread) but doesn’t wait for it to finish.Non-blocking call – the calling thread continues immediately.Useful when you don’t care about the result or don’t want to block the calling thread.Syntax (Windows Forms Example): this.BeginInvoke(new Action(() => {label1.Text = "Updated from BeginInvoke"; })); Use case: When you want to safely update the UI asynchronously without blocking the background. | Feature | Invoke() | BeginInvoke() | |-------------------|------------------------------------|---------------------------------------------------| | **Execution Type**| Synchronous | Asynchronous | | **Blocking** | Yes (waits for completion) | No (returns immediately) | | **UI Thread Safe**| Yes | Yes | | **Return Value** | Yes | No (unless callback or EndInvoke used) | | **Exception Handling** | On calling thread | On UI thread (may be swallowed if not handled) | | **Use Case** | When result is needed immediately | When fire-and-forget is fine |