Terms About Entreprise Systems

Reading Martin Fowler's book, Patterns of Enterprise Applications Architecture (link to buy on the references), I read some terms the author used in the context of Enterprise Applications, which I reproduce here.

• Response Time
  It's the amount of time a system takes to complete a task or request.
• Responsiveness
  It's about how quickly a system acknowledge a request as opposed to processing it.Latency
• It's the minimum time to get some response of the system.
• Throughput
  It's how much stuff the system can cod in a given amount of time.
• Load
  It's the statement of how much stress a system is under.
• Load Sensitivity
  It's a expression of how responsive time changes in relation with load.
• Performance
  It's either, performance (common sense), or throughput, depending on the case.
• Efficiency
  It's performance, divided by resources.
• Capacity
  It's an indication of maximum effective throughput or load.
• Scalability
  It's the measure of how adding resources affects performance.
• Vertical Scalability
  Means adding more power to single server to achieve better performance.
• Horizontal ScalabilityMeans adding more servers to achieve better performance.

About these topics, it's important to enforce the following point:

• Responsiveness
  It's sad how programmers - in general - don't care about it. A system, part of it, or even a screen with low responsiveness, decrease the User Experience, and sometimes it could cost the name of a hole system.

Reference

Fowler, Martin. Patterns of enterprise application architecture. Pearson Education. 2003.