How does constructor injection differ from property (setter) injection, and why is constructor injection generally preferred?

Constructor injection passes dependencies through the constructor, guaranteeing an object is NEVER in a partially-initialized state and making dependencies clearly visible in the class's public API; property injection sets dependencies via public properties AFTER construction, which can leave an object usable-but-broken if a required property is forgotten, and hides the true dependency requirements from the constructor signature.

// Constructor injection: dependency is guaranteed present and visible
public class OrderService {
  private readonly ILogger _logger;
  public OrderService(ILogger logger) { _logger = logger; } // impossible to construct without it
}

// Property injection: risky, can be forgotten
public class OrderServiceRisky {
  public ILogger? Logger { get; set; } // might be null if forgotten!
}