A ‘Segue’ in XCode is a transition between two screens (or View Controllers)

If you add a second View Controller to your storyboard you can ‘control click’ and drag between them to create a Segue
In this way the StoryBoard can now come to life and show the flow of screens in your app
Name your Segue Uniquely
If you highlight your newly created Segue – you can edit the ‘Identifier’ property in the Properties window
Give your Segue a unique name –
for example my Segue has been created to transition to a details screen so I can set the identifier as …

Performing a Segue at Run-Time
You can make the application perform the Segue at any time – this may be when the user presses a button or selects an item in a table
The line of code to do this is :
[self performSegueWithIdentifier:@"showDetailScreen" sender:nil];


For example if you have a button on your first view controller the action for the button press can be :
- (IBAction)actionButtonPress:(id)sender {
 [self performSegueWithIdentifier:@"showDetailScreen" sender:nil];


This will perform the Segue with the identifier “showDetailScreen” and the application will move to the next screen.