What's the difference between A<:B and +B in Scala?

Question

What\'s the difference between

[A <: B]

and

[+B]

in Scala?

Answer 1

for my Understanding:

---

The first is a parameter type bound, there a upper and lower typebounds in our case its a "type parameter A that is a subtype of B (or B itself).

---

The second is a Variance Annotation for a class defintion, in our case a covariance subclassing of B

---

Scala: + Java: ? extends T Covariant subclassing

Scala: - Java: ? super T Contravariant subclassing