A parameter usually refers to the limit wherein something would need to be done. There are a lot of people who use parameters for statistics but there are also instances when you would be using some boundaries on how you would like some things to be done.
There are times when you would like to show that there are certain conditions on how some things would need to be done. It can also stand for some sort of characteristic.
There are times when it would stand for a factor that can potentially make some changes to the outcome. When you say perimeter, this stands for the lines that are surrounding a certain area. This can also stand for the outermost limit of an item.