How does a computer direct the processing of information
Given that this is an introduction, I wouldn't get too concerned about the wording. It's normal to describe things in general terms, and then go into specifics later.
In a typical computer system, everything ultimately happens because some program running in the CPU made it happen. Even with external events such as interrupts (e.g. someone typed on a keyboard, or a network packet arrived), it is software's responsibility to decide what that means.
Of course, the central processing unit isn't necessarily the only processing unit that you have to think about. Modern peripherals (e.g. DMA controllers, network adapters, USB hubs, monitors) tend to be quite &quot;smart&quot;, and are often fully-realised computers in their own right.
For now, understand that the central processing unit is the programmable processing unit that a) directs the behaviour of the system as a whole, and b) is where general-purpose computation happens. This picture can be modified (e.g. to account for coprocessors) as you learn more.