What are the most important contemporary hardware, data storage, input, and output? 

What are the most important contemporary hardware, data storage, input, and output?
Technologies used in business?

• List and describes the various type of computers available to businesses today.
• Define the client/server model of computing, and describe the difference between two-tiered and n-tier client/server architecture.
• List the most important secondary storage media and the strengths and limitations of each.
• List and describe the major computer input and output devices.