Response Time, Throughput and Utilization

(a) Response Time
Response Time is the delay experienced when a request is made to the server and the server's response to the client is received. It is usually measured in units of time, such as seconds or milliseconds.

(b) Throughput
Throughput refers to the number of client requests processed within a certain unit of time. Typically, the unit of measurement is requests per second or pages per second. From a marketing perspective, throughput may also be measured in terms of visitors per day or page views per day.

(c) Utilization
Utilization refers to the usage level of different system resources, such as the server's CPU(s), memory, network bandwidth, and so forth. It is usually measured as a percentage of the maximum available level of the specific resource. Utilization versus user load for a Web server typically produces a curve.