From John Rayworth's excellent site (here):
Centrally controlled system - A hardware and/or software IT system in which all parts of it are controlled by a central controller/server/mainframe.
Distributed system: is a system in which components located on networked computers communicate and coordinate their actions by passing messages. The components interact with each other in order to achieve a common goal.
An important distinction
Please remember, for the rest of your life, the image below, and the distinction between centralized, decentralized, and distributed networks. Although we are learning about control, this idea is used in many different areas of computer science. Image used from https://openclipart.org/detail/277506/Centralized-Decentralized-and-Distributed-Networks who have released this under the Creative Commons Zero 1.0 License
Comparison of different systems
From the Dartford School:
Advantages of central system:
- Easier to administrate
- More control
Advantages of distributed systems:
- Quicker access
- Shared load
- Response more specific to environment
Disadvantages of distributed system:
- More complex to administrate
- Less control
Disadvantages of central systems:
- Slower access
- Computing load is on (usually) one device.
- Response to a less specific environment
Sample test question
- Click here for a question from an OLDER IB computer science test
- And please click here for the answers, but not until you've made a real effort!
- Compare a centrally controlled system with a distributed system