Vkontakte api_access_key?

Question

API

In Vkontakte, some people drop links, for example, this https://vk.com/video5016754_171144568?api_access_k...
What does api_access_key=### mean? How can this be used? Can attackers take advantage of this?
PS: I'm not a programmer, so please explain without complicated terminology.

Answer 1

How can this be used?

Get access to change/delete information. More precisely, full access.
Yes. Full access, but via API.