Dependency Inversion vs Dependency Injection

DependencyInjection.swift

class A {
    var b: B
    
    init(b: B) {
        self.b = b
    }
    
    func start() {
        b.doSomething()
    }
}

class B {
    func doSomething() {
    }
}

DependencyInversion.swift

protocol BInterface {
    func doSomething()
}
class A {
    var b: BInterface
    
    init(b: BInterface) {
        self.b = b
    }
    
    func start() {
        b.doSomething()
    }
}
class B: BInterface {
    func doSomething() {
    }
}
class C: BInterface {
    func doSomething() {
    }
}

FullDependency.swift

class A {
    var b: B
    
    init() {
        b = B()
    }
    
    func start() {
        b.doSomething()
    }
}

class B {
    func doSomething() {
    }
}