Acccess control is about who can access your data or resources, and the act of accessing may mean consuming, entering, or using. A couple common examples of access control is a physical lock such as a house lock, and a login prompt to a website. If anyone could gain access to your private data or systems, then that won’t be good would it? This is why access control in all your systems (desktop, website, car, house, etc) is important just like any other cyber security fundamental.