UIKit is the long-standing iOS UI framework. Everything on screen is a UIView arranged in a tree.
Common views
UILabel— text.UIButton— tappable actions.UIImageView— images.UITextField— single-line input.UIStackView— auto-arranges children in a row/column.
Creating a view in code
let label = UILabel()
label.text = "Welcome"
label.font = .boldSystemFont(ofSize: 22)
label.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(label)Handling a button tap
button.addTarget(self, action: #selector(tapped), for: .touchUpInside)
@objc func tapped() { print("Button tapped") }Tip: UIStackView dramatically reduces layout code — group related views inside it.
Summary
UIKit builds UI from a hierarchy of UIViews. You met the common controls and how to add and wire them.