Whatever your programs are doing, they often have to deal with vast amounts of
data. This data is usually represented and manipulated in the form of strings.
However, handling such a large quantity of input in strings can be very
ineffective once you start manipulating them by copying, slicing, and modifying.
Why?

Let's consider a small program which reads a large file of binary data, and
copies it partially into another file. To examine out the memory usage of this
program, we will use memory_