Elements of a Test Plan

I visited http://jakarta.apache.org/jmeter/usermanual/test_plan.html page today, as for long I was trying to find out what all these options, which come up with the right click, mean. These options are the Elements of a Test Plan. The three basic elements of a Test Plan are:
• Thread group
• Samplers
• Listeners
Others are:
▪ Controllers
▪ Logic Controllers
▪ Timers
▪ Assertions
▪ Configuration Elements
▪ Pre-Processor Elements
▪ Post-Processor Elements

The best place to understand what they are is to visit http://jakarta.apache.org/jmeter/usermanual/test_plan.html. They have been explained well there. For now I have been able to understand Thread Group. A Thread Group is the Big Daddy of a Test Plan. Every other element is the child or the sub-child of a 'Thread Group'

A Thread Group allows you to control:
- the number of threads
- the ramp-up period
- the number of times to execute the test

The two things 'number of threads' and 'number of times to execute the test' are very much understood but the confusing point is the ramp-up period. The ramp up period is nothing but the period after which the next thread start. It should be set with care. An simple example is... suppose we have 10 threads and we have set the ramp up period as 100, then all the threads will be up and running within 100 seconds. That implies, that Each thread will start 10 (100/10) seconds after the previous thread was begun.