Next step is to run the test cases, this is relevant even if you have created test cases manually. The first thing we need to add for any test plan is Thread Group.
Right Click on Test plan->Add-> Threads -> Thread Group
You can create test cases manually or record within Jmeter. A basic tool for providing the result data is Summary Report
Thread Group->Add-> Listener->Summary Report
There are additional reporting tools which can be used like Response Time Graph, Graph result etc.
By default the test will execute only once, but this is configurable in Thread Group properties.
You can see I have set users, rampup and loop as 5.
Number of threads or user will simulate number of users hitting the application simultaneously.
Rampup period will give time it takes for the peak load. For example you have set number of user as 1000, and ramp up period as 100 seconds, Jmeter will start with 1 (or more) user at second one and will increase load gradually. At 100th second, load will get raised to 1000 users.
Loop 1 means that all users will hit the application URL only once. a higher value, say 10 means each user hits the application 10 times. so 1000 users with loop of 10 means a total of 10000 hits on URL.
Once the test completes, we can see results in Summary report or other graphs