That's what I would define as weak AI. So yes, even algorithms which do not adapt their behaviors by learning, but can imitate intelligent human behavior to some extent would be weak AI, such as AI in video games.

Now strong AI would be: "the capability of a machine to originate intelligent human behavior"

This means the intelligent behavior would originate from the machine itself. Some Machine Learning algorithms exhibit strong AI, in that they find ways to even outperform a human, by themselves, through the learning process. Sometimes, we can't even understand why it chose to do what it did, but it appeared to be even more intelligent than what most human would have chosen to do themselves.

Now Artificial General Intelligence, or sometimes called strong AI also, but I think there needs to be a distinction as I explain before. This would be: "the capability of a machine to originate any intelligent human behavior"

The reason a lot of people are talking about true AI, AGI, strong AI, etc. today, is because Machine Learning is seen as the be all, end all of AI. Yet practitioners and scientists know that it is not, at least in its current form. Currently, it can solve simple decision tasks, probably the kind of decisions a person makes in under a second or two, like driving. But it does not solve them generally, so a person must train different models for each tasks.

At the same time, having a way to automate decision making of a single simple task is huge in terms of potential. There's so many things we can automate through this, and if we combine them, you can create even more complex autonomous machines. That's why people are excited. Though I understand that it is not as awesome as having found general AI, or AI which can make complex decisions. The dream of AI continues, but the practicality of it are closer then ever.