Traits allow you to share code between your classes without forcing you into a specific class hierarchy. Say you want all your classes to have the convenient utility method foo($bar); without traits you have two choices:
- implement it individually with code redundancy in each class
- inherit from a common (abstract) ancestor class
Both solution aren’t ideal, each with their different tradeoffs. Code redundancy is obviously undesirable, and inheriting from a common ancestor makes your class hierarchy design inflexible.
Traits solve this problem by letting you implement foo($bar) in a trait which each class can “import” individually, while still allowing you to design your class hierarchy according to business logic requirements, not language necessities.