Behind the scenes, a variable is a reserved section of the computer's memory. Just to make sure I'm clear, memory is temporary working space for the computer. Memory is transient - that is, things that are placed in memory are not stored there permanently. That is what the hard drive is for. Since memory is transient, and since variables are stored in the computer's memory, variables are by extension transient as well. Your script will use variables to temporarily store a piece of information that the script needs to keep track of.