MT4 Strategy Tester

I've gone through the sticky threads and searched a bit on the forexfactory forums, but cant seem to find the answer to my problem. In the strategy tester, when you go to 'expert properties' you have four columns, Value, Start, Step, and Stop. I can not for the life of me, understand what each column is for. If someone could please explain this and how it pertains to lots, takeprofits, etc.

I've been through a few guides i found on strategy tester but none explain the expert properties clearly.

For standard testing, you only need to concern yourself with the Value column. This will be the "value" the EA uses as it runs through the simulation.

The strategy tester also has the ability to optimize an EA. This is where you specify a range of values for one or more of the parameters for the EA and it will iterate over all possible combinations. For each parameter you place a check next to... it will start with the "start" value and increment by "step" until it reaches "stop".

Here's an example:

You've got an EA with a single param, "MoveAvgPeriod". You decide to see how well it performs using periods from 10 to 50, in steps of 5. Your start value would be 10, step would be 5 and stop would be 50. Make sense?

Ohhh i think i get it. Its used for Optimization, if you dont optimize, you dont need it. But lets say you do, for Stop loss, you want to test between 10 and 100 pips stop loss. start would be 10, step could be whatever (the incriment you want to increase by each time), and stop would be 100. Correct?

If so, now i get it. Thanks. Also do you have to have each thing you want to use checked? and is it totally ignored if its not checked? One more question though, when you go to expert properties and the optimization tab, it has all these limitations, what are they used for?