During Performance Testing using HP Load Runner , you will find the below terms.This Post will be useful for the PT new learners.

  

Load Runner Objects:

Vuser Scripts	A Vuser script describes the actions that a Vuser performs during the scenario. Each Vuser executes a Vuser script during a scenario Run. The Vuser scripts include functions that measure and record the performance of your application components
Load Test	Tests a system's ability to handle a heavy workload. A load test simulates multiple transactions or users interacting with the computer at the same time and provides reports on response times and system behavior.
Run-Time Settings	Run-Time settings allow you to customize the way a Vuser script is executed. You configure the run-time settings from the Controller or VuGen before running a scenario. You can view information about the Vuser groups and scripts that were run in each scenario, as well as the run-time settings for each script in a scenario, in the Scenario Run-Time Settings dialog box.
Scenario	A scenario defines the events that occur during each testing session. For example, a scenario defines and controls the number of users to emulate, the actions that they perform, and the machines on which they run their emulations
Scheduler Session	The Schedule Builder allows you to set the time that the scenario will start running, the duration time of the scenario or of the Vuser groups within the scenario, and to gradually run and stop the Vusers within the scenario or within a Vuser group. It also allows you to set the load behavior of Vusers in a scenario.
Session	When you work with the Analysis utility, you work within a session. An Analysis session contains at least one set of scenario results (lrr file). The Analysis utility processes the scenario result information and generates graphs and reports. The Analysis stores the display information and layout settings for the active graphs in a file with an .lra extension. Each session has a session name, result file name, database name, directory path, and type.
Transactions	A transaction represents an action or a set of actions used to measure the performance of the server. You define transactions within your Vuser script by enclosing the appropriate sections of the script with start and end transaction statement.
Vusers	Vusers or virtual users are used by LoadRunner as a replacement for human users. When you run a scenario, Vusers emulate the actions of human users working with your application. A scenario can contain tens, hundreds, or even thousands of Vusers running concurrently on a single workstation.

In the Load runner analysis , below terms you will find and here is what it is.

Graph Information:

Average	Average value of the graph measurement's
Hits	The number of HTTP requests made by Vusers to the Web server.
Maximum	Maximum value of the graph measurement's.
Measurement	This is the type of resource being monitored
Median	Middle value of the graph measurement's
Minimum	Minimum value of the graph measurement's.
Network Delay	The time it takes for a packet of data sent across the network to go to the requested node and return.
Network Path	The Network Path is the route data travels between the source machine and the destination machine.
Response time	The time taken to perform a transaction
Scale (or granularity)	In order to display all the measurements on a single graph, thus making the graphs easier to read and analyze, you can change the scale or (granularity) of the x-axis. You can either set measurement scales manually, view measurement trends for all measurements in the graph, or let Analysis scale them automatically. The Legend tab indicates the scale factor for each resource.
Standard Deviation (SD)	The square root of the arithmetic mean value of the squares of the deviations from the arithmetic mean.
Throughput	Throughput is measured in bytes and represents the amount of data that the Vusers received from the server
Vuser Load	When you run a scenario, the Vusers generate load or stress on the server. LoadRunner monitors the effect of this load on the performance of your application

Hope this helps :) 

IP Spoofing in HP Load runner

About IP Spoofing:

In order to replicate real world scenario when you do performance tests , it is required to test by enabling IP spoofing.

Usually network routers and application servers identify the client requests by their IP address and it will get cached.

So Load runner LG's , when you test requests will be made from the same IP address ( assuming your test scenario have only one LG). So network routers and application servers will cache the requests for better throughput and which in term miss the real life situations. To overcome this HP load runner have this feature ( IP Spoofing ) to make fool the devices that requests are coming from different IP address.

So you setup the fake IP address from the LG machine and enable this feature in Controller.

How to setup IP Spoofing.

 1)        Run IP Wizard (Start > Program Files > Load Runner > Tools > IP Wizard) on LG machines  to add the static IPs that we want to emulate in scenario.
           how many static IPs ?(based on number of Vusers to be executed on tests, if we use 100 users for scenarios, than 100 static IP's).

2)         Update the Load balancer/web servers routing table with new static IPs, this is done so that servers are able trace back to the client. If client and server are in same network and subnet mask then no need of modification is required.

3)         Re-start the LG’s where static IP’s are set to make modifications effect.

4)          Enable IP Spoofing ( Scenario > Enable IP Spoofer ) from Controller, before connecting to LG

Hope this helps :)